Seller Profit Doctor
Free fee and profit calculators for Etsy, Shopify and Amazon sellers: fees, break-even ad spend, shipping gaps and price for a target margin, each with dated sources. No sign-up.
Hosted MCP Server
npx add-mcp 'https://sellerprofitdoctor.com/api/mcp'Installs into Claude Code, Codex, Cursor and more
Documentation
When you ask Claude, ChatGPT or another AI assistant to use Seller Profit Doctor, it never sees our code. It reads a few short pieces of plain text, sends the figures you gave it, and gets an answer back that shows its working. This page shows those pieces, word for word, taken from the live tools themselves.
Green wooden letters A and I
15 free tools
Each one only reads
No sign-in
One address, no account or key
Nothing stored
Only an anonymous daily count
When an assistant uses these tools
An assistant doesn’t find and call our tools on its own. It uses them only once they’re connected: a seller adds our address as a connector in their assistant (Claude, ChatGPT or another app that supports MCP), turns them on from an assistant’s own directory where one lists them, or a developer builds them into a seller app or automation. Being in the official MCP Registry makes them findable; it doesn’t switch them on for anyone.
Once they’re connected, these are the moments they’re used:
- A money question in the middle of a chat. How much does Etsy take on a $30 sale?, My Etsy Ads ROAS is 1.5. Do they pay?, Should I move to Shopify Grow? and Is 25% off worth it for Black Friday?. Instead of answering fee rates from memory, the assistant can run the matching calculator and get exact figures, with the date of the rates and their sources.
- Fees on one Etsy sale
sellerprofit_etsy_fees - Break-even ROAS for Etsy Ads
sellerprofit_ads_breakeven - Which Shopify plan and billing fit your sales
sellerprofit_shopify_plan_fit - Is this sale worth it?
sellerprofit_sale_breakeven
- Fees on one Etsy sale
- Looking at a seller's shop. Look at my shop.. The assistant runs the free check-up from what the seller tells it, and gets the grade, the biggest losses and the fix for each.
- Shop profit check-up (Etsy, Shopify, Amazon)
sellerprofit_checkup
- Shop profit check-up (Etsy, Shopify, Amazon)
- A job done for a seller. Help me price this new item. and Should I ship this myself or let Amazon do it?. Pricing a new item, planning a sale, comparing Etsy, Shopify and Amazon on the same sale, Amazon shipping it or the seller shipping it, choosing a box size.
- Price for a target profit on Etsy
sellerprofit_price_for_margin - Is this sale worth it?
sellerprofit_sale_breakeven - Fees compared: one sale on Etsy, Shopify and Amazon
sellerprofit_compare_fees - Fees on one Amazon unit
sellerprofit_amazon_fees - What your box bills at
sellerprofit_box_billing
- Price for a target profit on Etsy
- A developer's seller app or automation. Someone building an assistant or an automation for sellers can use the tools for the fee math instead of keeping their own rate tables.
- Fee tables (dated, sourced): Etsy, Shopify, Amazon
sellerprofit_rates
- Fee tables (dated, sourced): Etsy, Shopify, Amazon
- Buying the full report for a seller. Buy me the full report.. An assistant can buy the full report for a seller through the paid server, kept apart from the free tools. See the paid tools below.
What the tools aren’t for. AI search answers, such as ChatGPT search, Perplexity or Google’s AI answers, read our web pages, not these tools.
1. How an assistant finds us
- A public directory. Our tools are listed in the official MCP Registry, the directory AI assistants use, as
com.sellerprofitdoctor/free-tools, with one address:https://sellerprofitdoctor.com/api/mcp. - A short greeting. When an assistant connects, our server introduces itself with a paragraph saying what each tool is for and what we keep.
- The tool list. The assistant asks what tools there are and gets 15, each with a name, a description and the inputs it accepts.
That’s everything it knows before it acts. Here is the greeting, exactly as it reads it:
The server’s greeting
Seller Profit Doctor's free tools work out where an online seller's money goes on Etsy, Shopify or Amazon (platform_supported: etsy, shopify, amazon). sellerprofit_checkup runs the full check-up for any of the three (set platform; etsy is the default) from a few Quiz v1 answers. The grade is a word such as Watch, with level 1 (Healthy) to 5 (Losing money); with too few answers there's no grade yet, and grade.missing lists what to ask. The other tools each answer one question: sellerprofit_etsy_fees (one Etsy sale's fees), sellerprofit_offsite_ads, sellerprofit_shipping_gap, sellerprofit_ads_breakeven, sellerprofit_price_for_margin (Etsy), sellerprofit_sale_breakeven (any of the three), sellerprofit_compare_fees (all three side by side), sellerprofit_ads_roas_breakeven (Meta and Google ads), sellerprofit_box_billing (dimensional weight), sellerprofit_shopify_plan_fit, sellerprofit_shopify_order_fees, sellerprofit_amazon_fees, sellerprofit_amazon_ads_breakeven, and sellerprofit_rates (any platform's fee table with sources). Money is US dollars; shares are fractions (0.1 is 10%). Bands and not-sure answers are fine: every result lists the defaults it used, so ask the seller for their real numbers and call again. Amazon's fulfillment, storage and returns fees use Amazon's 2026 rates but depend on the size and stock Amazon measures: those figures carry estimate: true and sit apart from the loss total. Say "about" and "estimated", and point the seller to Fee Preview. Every fix's dollar value holds at the seller's numbers if orders hold; say it that way, never as a promise. Each result carries the date of the rates and their sources: cite them. Fixed formulas; no AI computes a number. Free, no sign-in, numbers only; nothing you send is stored.
2. One tool, start to finish: fees on one Etsy sale
Take the Etsy fees calculator. Before the assistant uses it, this is the description it reads:
Works out Etsy's fees on one sale, line by line: the $0.20 listing fee, the 6.5% transaction fee, the 3% + $0.25 payment processing fee (also charged on sales tax), the 2.5% currency conversion when it applies, and the Offsite Ads fee (12% or 15%, at most $100) when the sale came from an Offsite Ad. It fits a seller who asks what Etsy takes from a sale, or what they keep from it before costs. Takes the item price and shipping charged; optionally the sales tax rate, whether it was an Offsite Ads sale and at which rate, and a currency mismatch. Returns each fee, the total, its share of the order and what's left, in US dollars, with the dated Etsy rules and their sources. Free, no sign-in. Takes numbers only; nothing is stored.
It then sees what it may send. One input is needed: itemPrice. The rest are optional, and each comes with its own words. For the sales tax rate it reads:
The sales tax rate the buyer paid, as a fraction (0.07 is 7%). Etsy charges its 3% processing fee on the tax too. Default 0.
Say a seller sold an item for $30 and the buyer paid $5 for shipping (example figures). This is the answer the assistant gets back:
What the assistant receives
On a $35.00 order (item $30.00 + shipping $5.00), Etsy takes $3.78, 10.8% of the order: listing $0.20, transaction $2.28, processing $1.30. About $31.22 is left before materials, packaging, the label and ads.
Etsy fees as of October 5, 2026 (Fees & Payments Policy) and July 31, 2026 (Payments Policy), checked October 13, 2026. Fixed formulas; no AI computes a number. Sources: https://web.archive.org/web/20261010144845/https://www.etsy.com/legal/fees ; https://web.archive.org/web/20261011064314/https://www.etsy.com/legal/etsy-payments/
Work it through on the website: https://sellerprofitdoctor.com/calculators/etsy-fees?utm_source=ai-assistant&utm_campaign=calculator
It ends with a link that opens the Etsy fees calculator on this website, which runs the same tool. The link is the same whatever the figures: nothing you sent is in it, only two tags that tell us the visit came from an AI assistant. Every tool’s answer ends the same way, with a link to its own page here.
The same answer also comes as tidy data the assistant can work with: each fee on its own line, the total, its share of the order, what’s left, the rules’ date and sources, so it can be checked, and the link.
3. When something is missing or wrong
The tool never answers with a bare “error”. Its reply names what to send instead, so the assistant can ask you rather than guess a number, and it never repeats what was sent. These are its real words:
- The item price left out
Required. Send a plain number, such as 30 or 4.5: no $ sign, letters or commas.
- A price below zero
Must be at least 0.01. Send US dollars, such as 30.
- An Offsite Ads rate it doesn’t know
Offsite Ads: send one of none, 12-percent, 15-percent, off.
Limits. The server takes up to 60 calls a minute from one address; past that it replies with how many seconds to wait. Calls from Claude’s own servers aren’t limited this way, because every Claude user’s calls come from them. A request can be up to 64 KB, far more than any tool call needs.
4. What we keep
Nothing you send is stored, as the server’s greeting tells every assistant. The tools take numbers and fixed choices only, never your name, email or shop, and what your assistant sends is used to work out the answer, then dropped. For each tool we keep one anonymous count a day of how many times it ran, with no figures and no address. Our logs keep one line per call: the tool’s name, how long it took and whether it answered. The site’s own uptime test isn’t counted. The details are in our privacy policy.
All 15 tools only read. None of them takes payment, sends an email or creates an account.
5. How we keep the answers honest
- Each calculator page on this website runs the same tool an assistant does, so an assistant and the page can’t give you different numbers. Our tests check the two against each other.
- Every 10 minutes the site connects to the server the way an assistant does and runs 5 real steps. A step passes only when the answer is the right one, not just when an answer comes back. You can see the result on the AI assistants page.
- The descriptions only describe: what a tool works out, what it takes and what comes back. None of them tells an assistant to use another tool.
6. All 15 tools, as an assistant sees them
Open any tool to see its description and every input, word for word.
The Etsy tools
One Etsy sale's fees, Offsite Ads, the shipping gap, Etsy Ads and the price for a target profit.
Fees on one Etsy sale
sellerprofit_etsy_fees
What the assistant reads
Works out Etsy's fees on one sale, line by line: the $0.20 listing fee, the 6.5% transaction fee, the 3% + $0.25 payment processing fee (also charged on sales tax), the 2.5% currency conversion when it applies, and the Offsite Ads fee (12% or 15%, at most $100) when the sale came from an Offsite Ad. It fits a seller who asks what Etsy takes from a sale, or what they keep from it before costs. Takes the item price and shipping charged; optionally the sales tax rate, whether it was an Offsite Ads sale and at which rate, and a currency mismatch. Returns each fee, the total, its share of the order and what's left, in US dollars, with the dated Etsy rules and their sources. Free, no sign-in. Takes numbers only; nothing is stored.
What it can send (1 needed, 4 optional)
itemPriceNeeded The item price on this sale, US dollars, before shipping.shippingChargedOptional What the buyer paid for shipping, US dollars (0 if free).salesTaxRateOptional The sales tax rate the buyer paid, as a fraction (0.07 is 7%). Etsy charges its 3% processing fee on the tax too. Default 0.offsiteAdsOptional Did this sale come from an Offsite Ad? none, or the rate the shop pays: 12-percent (the shop has sold $10,000 or more in any 12 months) or 15-percent (under $10,000). Default none; off is taken as none.currencyMismatchOptional True when the listing's currency differs from the payment account's (Etsy adds 2.5%). Default false.
What Offsite Ads cost on Etsy, and the price that covers it
sellerprofit_offsite_ads
What the assistant reads
Works out what Etsy's Offsite Ads cost a shop at its share of sales (12% or 15% of an attributed order, at most $100 an order), per order and per month, and the item price that covers the fee. It fits a seller who asks what Offsite Ads cost them, whether to price them in, or whether to opt out. Takes the item price, shipping charged, the shop's Offsite Ads rate (12-percent past $10,000, 15-percent under, or off), orders a month, and the share of sales from Offsite Ads if the seller knows it (else 10%, the figure Etsy gave at launch in 2020, flagged as a default). Materials and label cost are optional and add how far orders could fall before the price rise leaves the seller worse off. Returns the fee per attributed order and on average, the monthly and yearly cost, the price fix and its value if orders hold, and when opting out is possible. US dollars; dated Etsy rules with sources. Free, no sign-in. Takes numbers only; nothing is stored.
What it can send (3 needed, 5 optional)
itemPriceNeeded Typical item price, US dollars, before shipping.shippingChargedOptional What the buyer pays for shipping, US dollars (0 if free). Offsite Ads are charged on it too.offsiteAdsNeeded The shop's Offsite Ads rate: 12-percent (the shop has sold $10,000 or more in any 12 months; for life, no opt-out), 15-percent (under $10,000, Offsite Ads on), or off (opted out). none is taken as off.offsiteShareOptional Share of sales from Offsite Ads (Marketing > Offsite Ads): a fraction (0.1 is 10%), or a band. Left out: 10%, the figure Etsy gave at launch in 2020, flagged as a default.ordersNeeded Orders in a typical month: a number from 1 to 100,000 (Shop Manager > Stats > Orders), or a band. Over 300: send the number.materialsOptional Optional: materials per item, US dollars. With labelCost, adds how far orders could fall before the price fix leaves the seller worse off.labelCostOptional Optional: the shipping label, US dollars.packagingOptional Packaging per order in US dollars, or mailer (about $1), box (about $3) or not-sure. Left out: $1, a weakly sourced typical figure, flagged as a default.
The shipping gap on Etsy, and the fix price
sellerprofit_shipping_gap
What the assistant reads
Works out the shipping gap for an Etsy shop: what the label and packaging cost beyond what the buyer pays, per order and per month, and the fixes: the item price that covers the gap with shipping kept under Etsy's $6 search line, calculated shipping, and (for free-shipping shops) building shipping into items of $35 and up, each worth so much a month if orders hold. It fits a seller who charges less for shipping than the label costs, offers free shipping, or asks how to price shipping on Etsy. Takes the item price, shipping charged, label cost and orders a month; packaging (else $1 typical, flagged), the share of orders shipping free, the Offsite Ads rate and share, and materials are optional and sharpen the fix. Returns the gap, the fix price, every fix's monthly value and how far orders could fall before it leaves the seller worse off. US dollars; dated Etsy rules with sources. Free, no sign-in. Takes numbers only; nothing is stored.
What it can send (4 needed, 5 optional)
itemPriceNeeded Typical item price, US dollars, before shipping.shippingChargedNeeded What the buyer pays for shipping on an order that isn't free, US dollars (0 if shipping is always free).labelCostNeeded What the shipping label costs, US dollars (Shop Manager > Finances > Payment account > Shipping).packagingOptional Packaging per order in US dollars, or mailer (about $1), box (about $3) or not-sure. Left out: $1, a weakly sourced typical figure, flagged as a default.freeShippingShareOptional Share of orders that ship free: a fraction (0.25), or a band. Default none.ordersNeeded Orders in a typical month: a number from 1 to 100,000 (Shop Manager > Stats > Orders), or a band. Over 300: send the number.offsiteAdsOptional Optional: the shop's Offsite Ads rate. Fees on the higher price depend on it. Left out: estimated from orders × price, flagged. none is taken as off.offsiteShareOptional Optional: share of sales from Offsite Ads. Left out: 10%, the figure Etsy gave at launch in 2020, flagged as a default.materialsOptional Optional: materials per item, US dollars. Adds how far orders could fall before each fix leaves the seller worse off.
Break-even ROAS for Etsy Ads
sellerprofit_ads_breakeven
What the assistant reads
Works out the ROAS at which an Etsy shop's Etsy Ads pay for themselves (break-even ROAS = order ÷ what an ad order keeps after Etsy's fees and costs), the most an ad can cost per sale, and, with the shop's ROAS, what the ads gain or lose a month. It fits a seller who asks whether Etsy Ads are worth it, what ROAS they need, or whether to turn ads off. Takes the item price, shipping charged, materials, label cost, and the daily budget or exact monthly spend; packaging is optional ($1 typical, flagged) and ROAS from the Etsy Ads page adds the monthly gain or loss and the fix. Returns the margin, break-even ROAS, ad sales and earnings, the monthly gain or loss and, when the ads lose money, the fix and what it's worth. US dollars; dated Etsy rules with sources. Free, no sign-in. Takes numbers only; nothing is stored.
What it can send (3 needed, 5 optional)
itemPriceNeeded Typical item price, US dollars, before shipping.shippingChargedOptional What the buyer pays for shipping, US dollars (0 if free).materialsNeeded Materials and supplies per item, US dollars.labelCostNeeded The shipping label, US dollars.packagingOptional Packaging per order in US dollars, or mailer (about $1), box (about $3) or not-sure. Left out: $1, a weakly sourced typical figure, flagged as a default.adsDailyBudgetOptional Etsy Ads daily budget, US dollars, $1 or more (Etsy's smallest; assumed fully spent, 30 days a month). Or send adsMonthlySpend.adsMonthlySpendOptional Exact Etsy Ads spend last 30 days, US dollars. Or send adsDailyBudget.roasOptional Return on ad spend, last 30 days (Etsy Ads page): ad revenue ÷ ad spend, such as 1.5. Left out: only the break-even is returned.
Price for a target profit on Etsy
sellerprofit_price_for_margin
What the assistant reads
Works out the item price at which one Etsy order keeps a target profit after Etsy's fees (listing, 6.5% transaction, 3% + $0.25 processing), the average Offsite Ads fee, Etsy Ads spread over orders, materials, packaging and the label. The target is dollars per order or a share of the order; with neither, it returns the break-even price. It fits a seller who asks what to charge, how to price for a profit, or what their break-even price is on Etsy. Takes materials, label cost, shipping charged and the shop's Offsite Ads rate (12-percent, 15-percent or off); packaging, the Offsite share, ad spend with orders, and targetProfitPerOrder or targetMargin are optional. Returns the price, the order at that price line by line, the break-even price and what each extra dollar keeps. US dollars; dated Etsy rules with sources. Free, no sign-in. Takes numbers only; nothing is stored.
What it can send (3 needed, 7 optional)
materialsNeeded Materials and supplies per item, US dollars.labelCostNeeded The shipping label, US dollars.packagingOptional Packaging per order in US dollars, or mailer (about $1), box (about $3) or not-sure. Left out: $1, a weakly sourced typical figure, flagged as a default.shippingChargedOptional What the buyer pays for shipping, US dollars (0 if free).offsiteAdsNeeded The shop's Offsite Ads rate: 12-percent (past $10,000 in any 12 months), 15-percent (under $10,000, on), or off. none is taken as off.offsiteShareOptional Share of sales from Offsite Ads: a fraction, or a band. Left out: 10%, the figure Etsy gave at launch in 2020, flagged as a default.adsMonthlySpendOptional Optional: Etsy Ads spend a month, US dollars, spread over orders. Needs orders.ordersOptional Orders a month. Needed only with adsMonthlySpend.targetProfitPerOrderOptional The profit one order should keep after every cost, US dollars. Or send targetMargin. Neither: the break-even price.targetMarginOptional The profit one order should keep as a share of the order (item + shipping), such as 0.25. Or send targetProfitPerOrder.
For any of the three platforms
A sale or coupon, one sale's fees side by side, ads on Facebook, Instagram and Google, and what a box bills at.
Is this sale worth it?
sellerprofit_sale_breakeven
What the assistant reads
Works out how many more orders a sale or coupon needs just to keep the same profit a month, for one item on Etsy, Shopify or Amazon. Each platform's fees are worked out at the full price and again at the sale price: percentage fees fall with the price and fixed fees stay (Etsy's listing and processing fees, Shopify's 30¢), so the answer is extra orders = kept at full price ÷ kept on sale − 1. On Amazon the sale is a coupon plus the 2.5% coupon fee (third-party estimate); Amazon's public pages don't state whether the referral fee is on the price before or after the coupon, so both readings are returned. It fits a seller who asks whether 25% off is worth it, how many more sales a discount needs, or whether to join a sales event. Takes the platform, the item price, the discount percent, materials and label; optionally shipping charged, packaging ($1 typical, flagged), orders a month, and the platform's own field: Etsy Offsite Ads, Shopify plan, Amazon category and fulfillment fee. Returns one order at full price and on sale (price, each fee, costs, kept), the fee change, the extra orders needed and, with orders a month, the orders needed and what the sale costs if orders don't rise. When the sale price keeps nothing, it says no number of orders makes the sale pay. US dollars; dated rates with sources. Free, no sign-in. Takes numbers only; nothing is stored.
What it can send (5 needed, 7 optional)
platformNeeded Where the item sells.itemPriceNeeded The item's full price, US dollars, before shipping and before the discount.shippingChargedOptional What the buyer pays for shipping, US dollars (0 if free). The discount doesn't touch it. Default 0.discountPercentNeeded The discount, as a percent from 1 to 90 (25 is 25% off). It comes off the item price only.materialsNeeded Materials or product cost per item, US dollars (Amazon: landed cost).labelCostNeeded The shipping label per order, US dollars (0 if Amazon ships it).packagingOptional Packaging per order in US dollars, or mailer (about $1), box (about $3) or not-sure. Left out: $1, a weakly sourced typical figure, flagged as a default.ordersPerMonthOptional Optional: orders a month at full price now, a whole number. Adds the orders needed a month and what the sale costs if orders don't rise.offsiteAdsOptional Etsy only: do these orders come from an Offsite Ad? none, or the shop's rate: 12-percent (past $10,000 in any 12 months) or 15-percent. Left out: none (no Offsite Ads fee). off is taken as none.shopifyPlanOptional Shopify only: the plan, which sets the Shopify Payments card rate. Left out: basic, flagged.categoryOptional Amazon only: the referral category, or not-sure. Left out: Everything Else (15%), flagged.fulfillmentFeeOptional Amazon only: the FBA fee per unit (Fee Preview) when Amazon ships it, US dollars. It stays the same on sale. Left out: 0 (the seller ships), flagged.
Fees compared: one sale on Etsy, Shopify and Amazon
sellerprofit_compare_fees
What the assistant reads
Works out the fees on one sale on Etsy (listing, transaction, processing; Offsite Ads optional), on a Shopify store (card fee by plan through Shopify Payments) and on Amazon (referral fee by category, the Individual plan's per-item fee, an optional FBA fee the seller types), side by side, each column equal to that platform's single fee tool; with orders a month, Shopify's plan and Amazon's Professional plan are spread over each order. It fits a seller who asks which platform takes less of a sale, Etsy vs Shopify vs Amazon fees, or which is cheaper to sell on. Takes the item price and shipping charged; optionally orders a month, the Offsite Ads rate, the Shopify plan, the Amazon category, plan and FBA fee. Returns each platform's fee lines, fixed cost per order, total, what's left and its share of the sale, and which costs least at these numbers, with the caveat that fees are one part of the choice. US dollars; dated rates with sources. Free, no sign-in. Takes numbers only; nothing is stored.
What it can send (1 needed, 8 optional)
itemPriceNeeded The item price on the sale, US dollars, before shipping and tax.shippingChargedOptional What the buyer pays for shipping, US dollars (0 if free).ordersPerMonthOptional Orders a month, 1 to 100,000: spreads the fixed monthly costs (Shopify's plan, Amazon's Professional plan) over each order. Left out: fees on the sale only, before monthly plans (plansCounted false).etsyOffsiteAdsOptional Etsy: did the sale come from an Offsite Ad? none, 12-percent (shops past $10,000 a year) or 15-percent. Left out: none, flagged. off is taken as none.shopifyPlanOptional Shopify: the plan, paid through Shopify Payments. Left out: basic, flagged.shopifyBillingOptional Shopify: how the plan is billed, used with ordersPerMonth. Left out: monthly.amazonCategoryOptional Amazon: the category, which sets the referral fee. Left out: Everything Else (15%), flagged.amazonFulfillmentFeeOptional Amazon: the FBA fee per unit (Fee Preview in Seller Central) when Amazon ships it. The Amazon sale is then the item price alone (no shipping charged), and the fee replaces the label. Left out: the seller ships, and the buyer pays shippingCharged.amazonPlanOptional Amazon: professional ($39.99 a month) or individual ($0.99 an item). Left out: professional, flagged.
Break-even ROAS for Facebook, Instagram and Google ads
sellerprofit_ads_roas_breakeven
What the assistant reads
Works out the ROAS (ad revenue ÷ ad spend, as Meta or Google reports it) at which Facebook, Instagram or Google ads pay for themselves, when the ad sends buyers to a Shopify store, an Etsy listing or an Amazon listing, with that platform's own fees on the order. Break-even ROAS = order ÷ what one ad order keeps after the platform's fees, product, label, packaging and refunds; that amount is also the most an ad can cost per order. It fits a seller who asks what ROAS they need, why ads with a ROAS of 3 still lose money, or whether to pause Meta or Google ads. Takes the item price, product cost and label; optionally the platform (shopify default), shipping charged, packaging ($1 typical, flagged), the refund share, and the platform's own field (Shopify plan, Amazon category and fulfillment fee). The monthly ad spend with the reported ROAS or ad revenue adds the monthly gain or loss and the fix; all orders a month check the ad platform's count against the seller's own orders. Returns the order line by line, what an ad order keeps, the margin, the break-even ROAS, and with spend the monthly gain or loss. Says that Meta and Google count purchases with their own attribution windows, so their ROAS can differ from the store's own orders. US dollars; dated rates with sources. Free, no sign-in. Takes numbers only; nothing is stored.
What it can send (3 needed, 11 optional)
platformOptional Where the ad sends buyers: shopify (the store), etsy (an Etsy listing) or amazon (an Amazon listing). Left out: shopify, flagged.itemPriceNeeded The average order before shipping, US dollars: what the buyer pays for the item (one item an order).shippingChargedOptional What the buyer pays for shipping on that order, US dollars (0 if free). Left out: 0, flagged.productCostNeeded Product or materials cost per order, US dollars (Amazon: landed cost).labelCostNeeded The shipping label per order, US dollars (0 if Amazon ships it).packagingOptional Packaging per order in US dollars, or mailer (about $1), box (about $3) or not-sure. Left out: $1, a weakly sourced typical figure, flagged as a default.refundShareOptional Optional: the share of orders refunded in full, a fraction from 0 to 0.9 (0.05 is 5%). A refunded order is counted as: the item comes back and can be sold again, the buyer pays the return label, and the seller loses the label, packaging and the fees the platform doesn't return. Left out: no refunds, flagged.adSpendMonthlyOptional Optional: ad spend in the last 30 days on Meta (Facebook, Instagram) or Google, US dollars. With roas or adRevenue it gives the monthly gain or loss.roasOptional The ROAS the ad platform reports (Meta Ads Manager or Google Ads, last 30 days): ad revenue ÷ ad spend, as a plain number such as 2.5. Google shows ROAS as a percent: 250% is 2.5. Or send adRevenue with adSpendMonthly. Left out: only the break-even is returned.adRevenueOptional Optional: the purchase value the ad platform reports for the last 30 days, US dollars. Send with adSpendMonthly; ROAS = adRevenue ÷ adSpendMonthly.ordersPerMonthOptional Optional: all the orders the store or shop had in the last 30 days, from every source, a whole number. Send with adSpendMonthly: checks the ad platform's count against your own orders.shopifyPlanOptional Shopify only: the plan, which sets the Shopify Payments card rate. Left out: basic, flagged.categoryOptional Amazon only: the referral category, or not-sure. Left out: Everything Else (15%), flagged.fulfillmentFeeOptional Amazon only: the FBA fee per unit (Fee Preview) when Amazon ships it, US dollars. Left out: 0 (the seller ships), flagged.
What your box bills at
sellerprofit_box_billing
What the assistant reads
Works out the billable weight of one box with USPS (Priority Mail, Ground Advantage), UPS (Daily Rates and Retail Rates) and FedEx, from its outside size in inches and its actual weight, with each carrier's 2026 dimensional weight rules: sides rounded up to whole inches, cubic inches ÷ the divisor (139 for USPS since July 12, 2026, only for boxes over 1 cubic foot; UPS 139 Daily, 166 Retail; FedEx 139), rounded up to a pound, and the larger of that and the actual weight. It fits a seller who asks why a label cost more than the weight suggests, whether a box is too big, what dimensional weight a box has, or whether a smaller box would bill less. Takes lengthIn, widthIn, heightIn and weightLb or weightOz; optionally otherBox (a second box size) to compare. UPS and FedEx bill a large box (over 96 in long or over 130 in length plus girth) at least 90 lb; USPS prices by weight up to 108 in length plus girth (Ground Advantage commercial takes up to 130 in at a flat oversized price), and its row shows no billable weight past that; a box over 165 in length plus girth is refused. Returns per carrier the size weight, the billable weight, whether it bills on actual or size weight, and the largest box that still bills on the actual weight; USPS Ground Advantage cubic fit as information; warnings; and notes. No label prices (they depend on zone and account); divisors can differ by account. Dated carrier rules with sources. Free, no sign-in. Takes numbers only; nothing is stored.
What it can send (3 needed, 3 optional)
lengthInNeeded Length, inches, measured on the outside of the box (decimals are fine: 15.2).widthInNeeded Width, inches, measured on the outside of the box (decimals are fine: 15.2).heightInNeeded Height, inches, measured on the outside of the box (decimals are fine: 15.2).weightLbOptional The packed box's actual weight, pounds (3.2 is 3.2 lb), up to 70. Or send weightOz.weightOzOptional The packed box's actual weight in ounces (16 oz is 1 lb). Or send weightLb.otherBoxOptional Optional: a second (usually smaller) box to compare, inches, at the same weight. Adds what it bills at and the pounds it changes with each carrier.
Shopify
Which plan fits a store's sales, and every fee on one order.
Which Shopify plan and billing fit your sales
sellerprofit_shopify_plan_fit
What the assistant reads
Works out which Shopify plan (Basic, Grow, Advanced) costs least at a store's card sales: each plan's price plus the card fees that change with the plan (or Shopify's third-party fee on sales through another processor), the card sales above which each move up pays for itself, on monthly and yearly billing, and what yearly billing takes off the price. It fits a seller who asks whether to upgrade or downgrade their Shopify plan, whether yearly billing is worth it, or why a bigger plan costs them more. Takes monthly card sales (US dollars), the current plan, billing and processor; with both processors, the share Shopify Payments handles. Returns every plan's cost, the cheapest plan on the current billing and on either billing, the break-even sales, and the yearly-billing difference, with the dated Shopify rates and sources. A move's value holds at these sales; below the break-even the bigger plan costs more. Free, no sign-in. Takes numbers only; nothing is stored.
What it can send (4 needed, 2 optional)
monthlyCardSalesNeeded Online card sales a month, US dollars (order totals with shipping): what the card fees are charged on.currentPlanNeeded The store's plan (Settings > Plan). Plus is priced per store and Starter's figures aren't on Shopify's pricing page, so neither is compared here.billingNeeded How the plan is paid now.processorNeeded How card payments arrive (Settings > Payments): shopify-payments, another (Stripe, Square and others; Shopify then adds its third-party fee), or both.shopifyPaymentsShareOptional With both: the share of sales Shopify Payments handles, a fraction. Left out: half, flagged.premiumCardShareOptional Share of card sales on premium cards (Amex, business cards), which pay a higher rate on every plan. Default 0.
Fees on one Shopify order
sellerprofit_shopify_order_fees
What the assistant reads
Works out every fee on one order of a US Shopify store, line by line: the Shopify Payments card fee by plan (premium cards optional), the international card and currency conversion fees, the 1.25% for mixing Shopify Payments with another card processor, another processor's own fee and Shopify's third-party fee on top (2%, 1% or 0.6% by plan), and the PayPal exemption from that fee when Shopify Payments is the main processor. It fits a seller who asks how much Shopify takes per sale, what one order costs in fees, or what's left of an order. Takes the item price, shipping charged, the plan (basic, grow, advanced) and how the order was paid; orders a month, billing and the app bill put the plan price and apps on each order. Returns each fee with its working, the total, its share of the order and what's left, and with orders the plan and apps per order. US dollars; dated Shopify rates with sources. Free, no sign-in. Takes numbers only; nothing is stored.
What it can send (3 needed, 9 optional)
itemPriceNeeded What the buyer pays for the items on this order, US dollars, before shipping and tax.shippingChargedOptional What the buyer pays for shipping, US dollars (0 if free).planNeeded The store's plan (Settings > Plan). Plus is priced per store and Starter's rates aren't on Shopify's pricing page.processorNeeded How this order was paid: shopify-payments (the store's only card processor); another (Stripe, Square and others, or PayPal on a store without Shopify Payments: Shopify adds its third-party fee); both (the store runs Shopify Payments beside another card processor: the 1.25% applies to what Shopify Payments handles); paypal (paid with PayPal on a store whose primary provider is Shopify Payments: no third-party fee).shopifyPaymentsShareOptional With both: the share of orders Shopify Payments handles, a fraction (1 when this order went through Shopify Payments, 0 when through the other one). Left out: half, flagged.otherProcessorPercentOptional With another, both or paypal: that company's rate as a percent (2.9 is 2.9%). Send with otherProcessorCents. Left out: 2.9% + 30¢ (Stripe's standard rate), or 3.49% + 49¢ for paypal (the PayPal Wallet starting rate on Shopify's pricing page), flagged.otherProcessorCentsOptional That company's fixed fee per sale, in cents (30 is 30¢). Send with otherProcessorPercent.premiumCardShareOptional With shopify-payments or both only: the share of Shopify Payments card sales on premium cards (Amex, business cards), which pay a higher rate; 1 when this order was on one. Default 0.foreignShareOptional With shopify-payments or both only: the share of Shopify Payments sales paid by buyers abroad in another currency (1% international card fee + 1.5% conversion); 1 when this order was. Default 0.ordersPerMonthOptional Orders a month, a whole number from 1 to 100,000. Spreads the plan price and the app bill over each order. Left out: per-order fees only.billingOptional How the plan is paid (price per month). Needs ordersPerMonth. Default monthly.appsMonthlyOptional The monthly app bill, US dollars. Needs ordersPerMonth. Default 0.
Amazon
The fees on one unit, and where Sponsored Products stop paying.
Fees on one Amazon unit
sellerprofit_amazon_fees
What the assistant reads
Works out Amazon's fees on one unit at a price: the referral fee for the category (official, with the $0.30 minimum where the category has one), the $1.80 media closing fee (official), and for FBA an estimate of the fulfillment fee from Amazon's 2026 rate cards by size tier and weight, with the 3.5% fuel and logistics surcharge, and the peak-season fee from October 15 to January 14. It fits a seller who asks what Amazon takes on a sale, what FBA costs for an item, whether a price sits just over a fee line, or whether FBA or shipping it themselves costs less. Takes the price, category, fba or fbm, and for FBA the packed size and weight bands (or the packed dimensions); for FBM, the shipping the buyer pays. Or takes both (with packed, labelCost and, optionally, packaging, minutesPerOrder with hourlyValue, unitsPerMonth, inboundSplit and freightToAmazon) and compares Amazon shipping it with the seller shipping it for the same item, outside peak and from October 15 to December 31: each side's costs and what's left per unit, storage from the packed size, monthly totals, and the label + packaging + time where the answer flips. Assumes the Professional selling plan (the Individual plan adds $0.99 an item). Returns each fee, the total outside and in peak, what's left, and the price lines where a fee steps; a line whose reading Amazon doesn't confirm is marked verified: false. The FBA figure is estimate: true; Amazon's Fee Preview shows a seller's real fee. Dated rates with sources. Free, no sign-in. Takes numbers only; nothing is stored.
What it can send (3 needed, 11 optional)
priceNeeded The selling price on Amazon, US dollars.categoryNeeded The Amazon category, which sets the referral fee, or not-sure (Everything Else, 15%, flagged).fulfillmentNeeded fba (Amazon ships; adds the FBA fee estimate), fbm (the seller ships), or both (the two side by side for the same item: send packed and labelCost).sizeBandOptional FBA only (both needs packed): small-flat (fits 15 × 12 × 0.75 in), standard-box (up to 18 × 14 × 8 in) or bigger. Send with weightBand, or send packed.weightBandOptional FBA only (both needs packed): the packed weight band (the top of the band is used; over-3lb has no top, so it is billed from 3 lb and heavier items cost more: send packed for a closer number). Send with sizeBand.packedOptional The packed size and weight, as Amazon measures it: makes the FBA estimate exact to the rate card (with dimensional weight). Required with both: it can change which side leaves more, and gives the storage (cubic feet).shippingChargedOptional FBM or both: what the buyer pays for shipping when the seller ships, US dollars (0 if free). The referral fee is charged on price + shipping. Default 0.labelCostOptional both (required): what the seller's shipping label costs per order, US dollars.packagingOptional both: packaging per order, US dollars. Left out: $1, a weakly sourced typical figure, flagged.minutesPerOrderOptional both: minutes the seller spends packing and shipping one order. Send with hourlyValue. Left out: the seller's time isn't counted (said).hourlyValueOptional both: what an hour of the seller's time is worth, US dollars. Send with minutesPerOrder.unitsPerMonthOptional both: units sold a month; adds monthly totals.inboundSplitOptional both: how stock goes to Amazon: minimal (one location; Amazon charges a placement fee), partial (2–3 locations, offered only for bulky sizes; a standard-size unit is priced as minimal), or optimized (Amazon's split, no placement fee). Extra-large pays none. Left out: placement isn't counted (said).freightToAmazonOptional both: the seller's own freight per unit to send stock to Amazon, US dollars. Left out: not counted (said).
Break-even ACoS for Amazon ads
sellerprofit_amazon_ads_breakeven
What the assistant reads
Works out the ACoS (ad spend ÷ the sales the ads bring) at which Amazon Sponsored Products pay for themselves: what a unit an ad brings keeps before the ad (after the referral fee, the FBA fee estimate or the label and packaging, storage and the landed cost) as a share of what the buyer pays. Gives it outside peak season and in peak (October 15 to January 14), when the FBA peak fee lowers it. It fits a seller who asks what ACoS they need, whether their Amazon ads pay, or what to bid. Takes the price, category, fba or fbm, the packed size and weight bands or the packed dimensions (FBA) or shipping charged (FBM), and the landed cost. Optional: the monthly ad spend with the ACoS (or the ad sales) for the monthly gain or loss and the fix, and the conversion rate for the highest cost per click that pays. Amazon publishes no ACoS benchmark: the seller's own break-even is the test. The FBA fee and storage are estimates (estimate: true); Amazon's Fee Preview shows a seller's real fee. Assumes the Professional plan. Dated rates with sources. Free, no sign-in. Takes numbers only; nothing is stored.
What it can send (4 needed, 10 optional)
priceNeeded The selling price on Amazon, US dollars.categoryNeeded The Amazon category, which sets the referral fee, or not-sure (Everything Else, 15%, flagged).fulfillmentNeeded fba (Amazon ships; adds the FBA fee estimate) or fbm (the seller ships).sizeBandOptional FBA: small-flat (fits 15 × 12 × 0.75 in), standard-box (up to 18 × 14 × 8 in) or bigger. Send with weightBand, or send packed.weightBandOptional FBA: the packed weight band (the top of the band is used; over-3lb has no top, so it is billed from 3 lb and heavier items cost more: send packed for a closer number). Send with sizeBand.packedOptional The packed size and weight, as Amazon measures it: makes the FBA estimate and the size and weight checks exact to the rate card.shippingChargedOptional FBM: what the buyer pays for shipping, US dollars (0 if free). The referral fee is charged on price + shipping. Default 0.landedCostNeeded What one unit costs the seller, delivered: product, freight, duties and prep, to Amazon's door (FBA) or the seller's (FBM). US dollars.labelCostOptional FBM: what the shipping label costs, US dollars. Left out: shipping is treated as breaking even (label = shipping charged − packaging), flagged.packagingOptional FBM: packaging per order, US dollars. Left out: $1, a weakly sourced typical figure, flagged.adSpendOptional Sponsored Products spend, last 30 days, US dollars (Campaign Manager). With acos or adSales it gives the monthly gain or loss.acosOptional ACoS, last 30 days (Campaign Manager): ad spend ÷ the sales the ads brought, as a fraction (0.3 is 30%). Or send adSales with adSpend.adSalesOptional Sales the ads brought, last 30 days, US dollars (Campaign Manager). Send with adSpend; the ACoS is adSpend ÷ adSales.conversionRateOptional Orders ÷ clicks on the ads, last 30 days (Campaign Manager), as a fraction (0.1 is 10%). Adds the highest cost per click that still pays.
The check-up and the fee tables
The same free check-up as on this website, and each platform's dated, sourced fee table.
Shop profit check-up (Etsy, Shopify, Amazon)
sellerprofit_checkup
What the assistant reads
Runs the free profit check-up for an Etsy shop, a Shopify store or an Amazon seller. Returns the grade (a word such as Watch, with level 1 Healthy to 5 Losing money), what one order (Amazon: one unit) and the month keep after fees, ads and costs, the loss total, and the top 3 losses, each with its fix and what it's worth a month at the seller's numbers if orders hold. It fits a seller who asks where their money goes, whether their shop is healthy, or what to fix first. Takes platform (etsy is the default) and that platform's Quiz v1 answers; each field says what it takes. Bands and "not-sure" are accepted: every default used is listed (isDefault). There may be no grade yet: with too few answers, level is null, word is "Not enough answers yet", and grade.missing lists the answers a grade needs; losses found still show. Amazon: fulfillment, storage and returns dollars are estimates from Amazon's 2026 rates for the size and stock given (estimate: true, in estimatedLeakTotal, apart from leakTotal); a typed fbaFee from Fee Preview makes that fee the seller's own. Money is US dollars; shares are fractions (0.1 is 10%). Every result carries the dated rates with sources. Free, no sign-in. Takes numbers only; nothing is stored.
With platform etsy: what it can send (6 needed, 8 optional)
platformOptional etsy (the default when left out).ordersNeeded Orders in a typical month: a number from 1 to 100,000 (Shop Manager > Stats > Orders), or a band. Over 300: send the number.itemPriceNeeded Typical item price in US dollars, before shipping (the item sold most).materialsOptional Materials and supplies for one item, US dollars. Or send materialsShare when the seller isn't sure.materialsShareOptional When the seller isn't sure of materials: the share of the price they take, a fraction or a band.shippingChargedNeeded What the buyer pays for shipping on a typical order, US dollars (0 if free).labelCostNeeded What the shipping label costs, US dollars, or not-sure (shipping is then treated as breaking even and shown as couldn't check).tenKNeeded Has the shop sold $10,000 or more in any 12 months? yes (Offsite Ads 12% for life), no-offsite-on (15%, can opt out), no-opted-out (no Offsite fee), not-sure (estimated from orders × price).etsyAdsNeeded Etsy Ads daily budget: no, a band (dollars a day), or yes with adsDailyBudget or adsMonthlySpend. 25-plus needs adsDailyBudget.adsDailyBudgetOptional Etsy Ads daily budget, US dollars (assumed fully spent, 30 days a month).adsMonthlySpendOptional Exact Etsy Ads spend last 30 days, US dollars. Wins over the daily budget.roasOptional Etsy Ads ROAS, last 30 days (Etsy Ads page): a number, a band, or not-sure. Only when the shop runs ads.deeperOptional Optional go-deeper answers; each one sharpens the result.targetProfitPerOrderOptional Profit per order the seller wants on top of costs, US dollars (used by the price fix when orders lose money). Default 0.
With platform shopify: what it can send (9 needed, 9 optional)
platformNeeded shopify, for a store on the seller's own Shopify site.ordersNeeded Orders in a typical month (Analytics > Orders): a number, or a band. Over 1,000: send the number.orderValueNeeded A typical order before shipping and tax, US dollars (average order value).productCostOptional What the products in that order cost the seller (COGS), US dollars. Or send productCostShare when not sure.productCostShareOptional When the seller isn't sure of product cost: its share of the order, a fraction or a band.shippingChargedNeeded What the buyer pays for shipping on a typical order, US dollars (0 if free).labelCostNeeded What the shipping label costs, US dollars, or not-sure (shipping is then treated as breaking even and shown as couldn't check).planNeeded The plan (Settings > Plan), or not-sure (plan fit and billing then can't be checked).billingNeeded How the plan is paid, or not-sure.paymentsNeeded How card payments arrive (Settings > Payments): shopify-payments, another (for example Stripe or Square), both, or not-sure (the third-party fee checks then can't run).otherProcessorPercentOptional The other card company's rate as a percent (2.9 is 2.9%). Send with otherProcessorCents. Left out: 2.9% + 30¢, flagged.otherProcessorCentsOptional The other card company's fixed fee per sale, in cents (30 is 30¢). Send with otherProcessorPercent.shopifyPaymentsShareOptional With both: the share of sales Shopify Payments handles (Shop Pay, local methods), a fraction. Left out: half, flagged.adsNeeded Ads a month (Meta, Google, TikTok): none, a band (US dollars a month), or yes with adsMonthlySpend. 3000-plus needs adsMonthlySpend.adsMonthlySpendOptional Ad spend a month, US dollars. Wins over the band.roasOptional Sales from Shopify (not Ads Manager) ÷ ad spend, last 30 days: a number, a band, or not-sure. Only when the store runs ads.deeperOptional Optional go-deeper answers; each one sharpens the result and adds a check.targetMarginOptional The margin the seller wants on each order after every cost, a fraction (0.2 is 20%), for the target price.
With platform amazon: what it can send (7 needed, 12 optional)
platformNeeded amazon, for a seller on Amazon's US marketplace.unitsNeeded Units sold in a typical month (Business Reports > Sales Dashboard > Units Ordered): a number, or a band. Over 5,000: send the number.priceNeeded The selling price on Amazon, US dollars.landedCostOptional Landed cost per unit (product + freight + duties + prep, to Amazon's door), US dollars. Or send landedCostShare when not sure.landedCostShareOptional When the seller isn't sure of landed cost: its share of the price, a fraction or a band.categoryNeeded The Amazon category, which sets the referral fee, or not-sure (Everything Else, 15%, flagged).fulfillmentNeeded Who ships: fba (Amazon), fbm (the seller), or both.planNeeded professional ($39.99 a month), individual ($0.99 an item), or not-sure.fbaFeeOptional FBA or both: the FBA fee per unit from Fee Preview or the Revenue Calculator, US dollars, all-in. Turns the estimate into the seller's own number. Or send sizeBand and weightBand.sizeBandOptional FBA or both, when the FBA fee isn't known: small-flat (fits 15 × 12 × 0.75 in), standard-box (up to 18 × 14 × 8 in), bigger. Send with weightBand.weightBandOptional FBA or both, when the FBA fee isn't known: the packed weight band. Send with sizeBand.shippingChargedOptional FBM or both: what the buyer pays for shipping per unit, US dollars (0 if free).labelCostOptional FBM or both: what the label costs per unit, US dollars, or not-sure.ppcNeeded Sponsored Products a month: none, a band (US dollars a month), or yes with ppcMonthlySpend. 5000-plus needs ppcMonthlySpend.ppcMonthlySpendOptional Sponsored Products spend a month, US dollars. Wins over the band.acosOptional ACoS, last 30 days (Campaign Manager): a fraction (0.3 is 30%), a band, or not-sure. Only when the seller runs Sponsored Products.deeperOptional Optional go-deeper answers; each one sharpens the result. packed (the packed size) makes the FBA estimate and the size and weight checks exact to the rate card.targetMarginOptional The margin the seller wants after every cost, a fraction of the price (0.2 is 20%), for the repricing fixes. Default 0: break-even.todayOptional Today's date, YYYY-MM-DD: picks the storage season and the peak window (October 15 to January 14). Default: today in Los Angeles.
Fee tables (dated, sourced): Etsy, Shopify, Amazon
sellerprofit_rates
What the assistant reads
Returns one platform's fee table, the one this server's numbers use: every fee and rule with its value, a plain label, its source link and the day it was checked, whether it's official or a third-party estimate, and both values where sources disagree, plus when the table is due for its next check. Etsy: listing, transaction, processing, Offsite Ads, Etsy Ads minimums, shipping lines, Etsy Plus, tax facts. Shopify: plan prices on both billings, card rates, the third-party processor fee, currency, chargebacks, Shopify Tax. Amazon: plans, referral by category, the media closing fee, FBA, size tiers, storage, aged stock, removal, returns, placement, low-inventory and peak fees (official, from Amazon's own pages), and coupon fees (third-party). It serves to cite a platform's fees, to answer what a fee is, or to check how current the numbers are. Takes no figures; platform defaults to etsy. Free, no sign-in. Nothing is stored.
What it can send (0 needed, 1 optional)
platformOptional Whose fee table. Default etsy.
Where it's listed
The free server is listed in these directories, so you can find it where you already look. The date is the day we last opened each listing and saw the server on it.
- Official MCP Registry. The MCP project's own list of servers. Ours is com.sellerprofitdoctor/free-tools, and other directories copy from it. Checked October 22, 2026.
- GitHub MCP Registry. GitHub's list of MCP servers, which GitHub's team reviews before adding a server. Ours was approved on October 21, 2026. Checked October 22, 2026.
- Glama. A directory of MCP servers that checks each one is online and lists its tools. Checked October 22, 2026.
Know a directory we should be in? Email support@sellerprofitdoctor.com.
The paid tools
Buying is kept apart, on a second server with 2 tools of its own, at https://sellerprofitdoctor.com/api/mcp/agent. sellerprofit_buy_report prepares the profit report or the full report and returns a payment link, and sellerprofit_report_status says where a purchase stands. Payment goes through Stripe. How it works is on the AI assistants page.
Try it in your own assistant
One address, no account, and what you send isn’t stored.