Amazon & e-commerce seller tools

This cluster covers the numbers that decide whether a listing is actually worth selling: what to charge, what you keep after marketplace fees, and how much you can afford to spend on ads before advertising eats your profit. Every fee-dependent input — referral fee, FBA fulfillment fee — is a field you fill in yourself rather than a hardcoded table, because those rates vary by category and change over time. Pull your current numbers from Amazon Seller Central's Revenue Calculator and the math here stays accurate regardless of when you use it.

All six tools are free, require no account, and calculate instantly as you type — nothing you enter is sent to our servers.

Which seller tool do you need?

Pricing a product? Start with the Profit Margin Calculator to get gross profit, margin and markup right, or to work backwards from a target margin to a required price.

Selling on Amazon FBA? Use the Amazon FBA Calculator to fold in referral fees, FBA fulfillment fees and other per-unit costs and get to a true net profit, margin and ROI, plus your break-even sale price.

Running Sponsored Products campaigns? The Break-Even ROAS & ACOS Calculator shows the ad-spend ceiling your margin can support, and a target ACOS for the profit you actually want to keep after ads.

Already have a PPC report? Upload it to the Amazon ACOS Calculator's report analyzer to find high-spend zero-order terms, ACOS overruns and scale-up candidates — all analyzed in your browser.

Setting a price from a supplier's cost or a target markup? Use the Markup Calculator to go from cost and a markup percentage straight to a selling price — and to see the margin percentage that markup actually produces, since the two are never the same number.

Managing stock levels or reviewing working capital? The Inventory Turnover Calculator turns your COGS and inventory values into a turnover ratio and days inventory outstanding (DIO), so you can spot slow-moving stock before it becomes a cash-flow problem.