ACoS Break-Even Calculator
Enter your selling price, product cost and Amazon fees and see how much ad spend a sale can carry before it loses money. You get unit profit before ads, break-even ACoS, a target ACoS for the margin you want, break-even ROAS, and a TACoS planner that blends ad and organic sales. It is for Amazon sellers setting bid targets per product. Everything runs in your browser; nothing is uploaded, stored or sent.
Example defaults, not quotes. Check the current Amazon fee pages for your category, size and weight. On 23 Oct 2026 that page listed most categories at 15%.
Calculating...
How it works, and what it does not cover
Unit profit before ads = price - product cost - referral fee (price x referral %) - fulfilment fee - other per-unit costs - returns allowance. The returns allowance is your returns rate multiplied by the fulfilment fee plus other costs, which assumes a returned unit is resellable and the sale is refunded.
Break-even ACoS = unit profit before ads / price. Break-even ROAS is its inverse (1 / break-even ACoS), the sales per ad dollar you need just to cover costs. Target ACoS = break-even ACoS - target margin, where the margin is a percent of price you want left after ads.
TACoS planner. Pick the share of total sales that come from ads. Total ACoS (ad spend over total sales) is called TACoS: target ACoS x ad share. Blended profit per unit is profit before ads minus price x TACoS, averaged over all units, ad-driven or organic. The planner uses your target ACoS as the ACoS for ad-attributed sales; change the margin to test other levels. Read ad share from your own Business Reports and ads console, because it moves with launches, seasons and budget.
What it leaves out
- Storage, long-term storage, inbound shipping, prep, subscription ($39.99/month Professional plan on the pricing page we read) and disposal fees. Spread them across units and enter them under other costs.
- Sales tax, income tax, currency effects and coupons or deals that cut the price.
- The halo effect: ads can lift organic rank, which is why launch campaigns sometimes run above break-even on purpose. This tool shows the cost of that choice; it does not value it.
- Variable fees: referral fees can be tiered by price (some categories use two rates) and carry minimums such as $0.30 per item. Enter the effective percentage for your price.
Results are arithmetic on the numbers you type, not advice. Where an Orbitloft or AdSpark product could be relevant, see the disclosure; this tool does not promote them.
Data last verified 2026-10-23. Prices, hours and rules change; confirm fees, limits and program terms with the official source before you rely on a number.
Sources
Related guides
Frequently asked questions
What is break-even ACoS?
It is profit per unit before ad spend divided by the selling price. If a $40 item leaves $18 after product cost, Amazon fees and other costs, break-even ACoS is 45%. At that ACoS an ad-attributed sale earns exactly zero profit.
How is target ACoS different from break-even ACoS?
Target ACoS is break-even ACoS minus the profit margin you want to keep on ad-attributed sales. With a 45% break-even and a 10% margin goal (as a share of price), the target is 35%.
Why does the calculator ask about returns?
Returned units usually cost you at least the fulfilment fee and any per-unit handling. The tool applies your returns rate to those two costs. It assumes returned units are resellable. If many come back damaged, add that loss to "other per-unit costs".
What is TACoS and how does the planner use it?
TACoS is ad spend divided by total sales, ad-attributed plus organic. The planner multiplies your ACoS by the share of sales that comes from ads, then subtracts the resulting ad cost per unit from profit before ads to show blended profit per unit.
Are the Amazon fee defaults current?
The 15% referral default is an example. On 23 October 2026 the Amazon selling pricing page described most categories at 15%, with others lower or higher. Fulfilment fees depend on size, weight and date, so the default is a placeholder. Check the current fee pages and edit every field.