Break Even ACoS
Last updated: February 17, 2026
What is the break even ACoS?
The break even ACoS (also: breakeven ACoS or BE-ACoS) is the Advertising Cost of Sales at which your advertising generates neither profit nor loss. It marks the point where your ad spend exactly equals the available contribution margin.
The break even ACoS is identical to your product's profit margin (contribution margin). If your actual ACoS is below the break even ACoS, you make a profit on every ad-driven sale. If it is above, you generate a loss.
Table of contents
The break even ACoS formula
The break even ACoS equals your product's percentage margin – that is, the share of the selling price that remains after deducting all costs (except advertising).
Break Even ACoS = (Contribution margin / Selling price) × 100
The contribution margin is the selling price minus all variable costs: product costs, Amazon fees (referral fee, FBA), shipping, and other variable expenses.
Relationship to the break-even bid
The break-even bid and the break even ACoS describe the same point from different perspectives:
- • Break Even ACoS: Percentage threshold for the ACoS
- • Break-Even Bid: Absolute maximum bid in dollars
A calculation example
Starting point
- • Selling price: $29.99
- • Product costs: $8.00
- • Amazon referral fee (15%): $4.50
- • FBA fees: $4.50
- • Other costs: $1.00
- • Contribution margin: 29.99 - 18.00 = $11.99
Calculation
Break Even ACoS = ($11.99 / $29.99) × 100 = 40%
This means: at an ACoS of 40%, you make neither profit nor loss. Any ACoS below 40% generates a profit, while any ACoS above it leads to losses on your ad-driven sales.
Interpretation and application
The break even ACoS serves as a point of reference for campaign management. However, it is not a rigid target but rather an important benchmark.
What your ACoS means relative to break even
ACoS < Break Even ACoS
You make a profit on every ad-driven sale
ACoS = Break Even ACoS
You reach the break-even point (neither profit nor loss)
ACoS > Break Even ACoS
You lose money on every ad-driven sale
Keep in mind: an ACoS above break even is not automatically bad. For product launches, to boost rankings, or for brand awareness, it can be strategically worthwhile to advertise temporarily above break even.
Frequently asked questions (FAQ)
Should my target ACoS always be below the break even ACoS?
For long-term profitability, yes. In the short term, however, there can be reasons to go higher: launching a product, building rankings, displacing competitors, or when the customer lifetime value is higher than a single sale.
Does every product have a different break even ACoS?
Yes, because every product has different margins. High-priced products with low costs have a higher break even ACoS. Low-priced or thin-margin products often have a very low break even ACoS, which makes profitable advertising harder.
Does the break even ACoS account for organic sales?
No, the break even ACoS only considers direct ad-driven sales. If you want to factor in the "halo effect" of advertising on organic sales, you should use TACoS as a complementary metric.
Related terms
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