Free tool

Break-even ACoS calculator

Find the exact ACoS at which an advertised sale stops making a profit. Enter your selling price, product cost and Amazon fees — then aim your campaigns below that line. Runs in your browser; nothing is stored.

Last updated: June 2026

What is break-even ACoS?

Break-even ACoS is the ACoS where an advertised sale makes zero profit — advertising consumes exactly the margin you had after product cost and fees. The formula is (selling price − product cost − Amazon fees) ÷ selling price × 100. A ₹1,000 item with ₹400 cost and ₹200 fees has a 40% break-even ACoS, so you target below 40% to stay profitable.

Break-even ACoS

40.0%

Stay below this to profit

Margin per sale (before ads)

₹400

40% of price

Browser-only math. Enter one combined fees figure (referral + FBA/fulfilment + per-unit costs).

Why break-even ACoS is the number that matters

Most "good ACoS" advice quotes a flat figure like 25% or 30%, but that is meaningless without your margins. A product with a 50% margin can run a 45% ACoS and still profit; a product with a 20% margin loses money at 25%. Your break-even ACoS turns a generic rule of thumb into a line that is actually true for your product.

Once you know it, the strategy is simple: keep your target ACoS below break-even on products you want to run profitably, and only go above it deliberately — for a launch, to defend a keyword, or to win rank you will monetise later. See how ACoS and margins connect on the ACoS calculator and the profit calculator.

Break-even ACoS — FAQ

What is break-even ACoS?
Break-even ACoS is the ACoS at which an advertised sale makes neither a profit nor a loss — your advertising eats exactly the margin you had left after product cost and Amazon fees. Run ads below this ACoS and each sale is profitable; run above it and you lose money on every advertised order.

How do you calculate break-even ACoS?
Break-even ACoS equals your profit margin before ad spend, as a percentage of the selling price: break-even ACoS = (selling price − product cost − Amazon fees) ÷ selling price × 100. If a ₹1,000 item costs ₹400 to make and ₹200 in fees, ₹400 margin remains — a 40% break-even ACoS.

What ACoS should I target then?
Target an ACoS comfortably below your break-even so each advertised sale still leaves real profit, not just zero. How far below depends on how much margin you want to keep versus how aggressively you want to grow. Many sellers aim for an ACoS that leaves at least half their margin intact.

Do I include all Amazon fees?
Include the per-unit costs that apply to a sale: the referral fee, FBA or fulfilment fee, and any per-unit storage or shipping you carry. This calculator takes one combined fees figure, so add them up first. The more complete your fee figure, the more accurate your break-even ACoS.

How does AIAdKing use my break-even ACoS?
In AIAdKing you set a target ACoS, and the nightly cycle moves bids toward it on the official Amazon Ads API — never blindly, always with a logged reason and a shadow-mode preview. Set your target below your break-even and the automation works to keep advertised sales profitable. It is a flat ₹2,499/month with no commission on ad spend.

Set a target ACoS below break-even — and let it hold.

AIAdKing moves bids toward your target every night, with a logged reason and a shadow-mode preview for every change. Connect Amazon and see it work before anything goes live.

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₹2,499/month (or ₹27,999/year) after trial. Cancel anytime.