Profit calculators for online sellers
Marketplace fees, fulfilment, advertising and returns all come out of the same number. These 24 calculators show you what is actually left — and every one shows the formula it uses.
All calculators
Grouped by the decision you are trying to make.
Profit & Pricing
Work out what you actually keep per unit, per order, and per sale after every fee has taken its cut.
Advertising
Find the break-even point on ad spend before you scale it — and the target you should hold campaigns to.
Inventory
How much to reorder, when to reorder it, and what slow-moving stock is quietly costing you each month.
Store Metrics
The handful of ratios that decide whether a store is healthy: conversion, order value, returns, abandonment.
Why the numbers are usually worse than expected
Fees are charged as a percentage of the selling price, not of your cost. That single detail is why adding a margin percentage to your cost price undercharges you, and why a product that looks profitable on a spreadsheet often is not. Advertising is the second leak: it is priced per order, while the margin it consumes is a share of revenue, so the two move independently as you scale.
None of this is a matter of opinion. It is arithmetic, and once it is written down the decisions get easier — usually pointing at price or unit cost rather than at more volume.