FBA Profit Calculator — NetMargin

Net profit and real margin for Amazon FBA. Versioned fee table, every field editable, nothing leaves your browser.

The FBA calculator that gets the fees right. ACCURATE, AUDITABLE FEES The fee table is versioned in a file and its effective date is on screen while you calculate ("Fees effective: Jan 2026"). Every line shows how the number was produced — the size tier, the billable weight, the price band, the surcharges. You always know which rate card you are looking at. EVERY FIELD EDITABLE Manual override on any calculated value. Overridden lines are marked, so your number is never confused with ours. You know your product better than a table does. ZERO SERVER All math runs in your browser. There is no API to be down and no "try again later". ZERO LOGIN, ZERO POP-UPS, ZERO TELEMETRY No account. No interstitials. Nothing about the products you look at leaves your machine — open your DevTools Network tab and check. WHAT IT CALCULATES · Referral fee, including tiered categories and per-item closing fees on media · FBA fulfillment fee by size tier, billable weight and price band · Dimensional weight, applied exactly where Amazon applies it · Monthly storage, cost of goods, inbound shipping, prep, advertising, returns reserve · Net profit, net margin, ROI and break-even price BULK ANALYSIS Drop your Fee Preview report from Seller Central and see the whole catalogue ranked by margin, using the fees Amazon actually charges you on each ASIN. The file never leaves your browser. Built for the 2026 US fee structure, including the price bands introduced in January and the fuel and logistics surcharge that starts in April. WHERE WE ARE NOT SURE, WE SAY SO Referral fees are verified against Amazon's published rate card. Standard-size fulfillment fees match across three independent sources. For oversize tiers the sources disagree, so the app tells you that on screen and points you at your Fee Preview instead of pretending to know. A calculator that hides its uncertainty is how the other ones lost their reputation. NetMargin is an independent tool. It is not affiliated with, endorsed by, or sponsored by Amazon. It calculates from the values you enter and a published fee table; it does not predict or guarantee any financial result. Always confirm against your Seller Central Fee Preview.