Break-Even ACOS Calculator
Find the exact ad spend your margin can support before you lose money, then check any campaign against it.
Break-even ACOS equals your profit margin before ad spend. Enter your per-unit numbers below.
How break-even ACOS works
ACOS (Advertising Cost of Sales) is ad spend divided by ad sales. Your break-even ACOS is simply your profit margin before ad spend: spend exactly that percentage and you make zero on the sale. Spend less, you profit. Spend more, you lose.
The formula
Profit before ads = price minus COGS minus Amazon fees. Break-even ACOS = that profit divided by price. To hit a target net margin, your max ACOS = break-even ACOS minus your target margin. Need your per-unit fee number? Get it from the FBA profit calculator.
ACOS vs TACOS
ACOS measures a single campaign. TACOS (Total ACOS) is ad spend divided by total sales, organic plus paid. A healthy TACOS sits around 10 to 15%, and a falling TACOS while sales grow means your ads are lifting organic rank too.
Frequently asked questions
How is break-even ACOS calculated?
Break-even ACOS equals your profit margin before advertising. Take price minus product cost minus Amazon fees, divide by price, and that percentage is the ACOS at which ad profit is zero.
What is a good ACOS on Amazon?
It depends on stage and margin. New products often run 40 to 50% to gain traction; established products target 15 to 25%. The real ceiling is your break-even ACOS, which this tool calculates.
What is the difference between ACOS and TACOS?
ACOS is ad spend over ad-attributed sales (campaign efficiency). TACOS is ad spend over total sales (the whole business). A healthy, falling TACOS signals your ads are driving organic growth.
Is a high ACOS always bad?
No. During a launch, a high ACOS that builds rank and reviews can be a smart investment. It only becomes a problem when it sits above your break-even ACOS on an established product.
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Get my free auditEstimates for planning only. Results depend on the accuracy of your per-unit cost and fee inputs.