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Break-even ROAS Calculator

Break-even ROAS. Calculate break-even ROAS and maximum CPA from average order value, product cost, shipping, fulfillment and percentage fees.

Formula reviewed September 1, 2026 · Runs locally in your browser
Quick answer

Break-even ROAS quick answer

Answer: Break-even ROAS is the minimum return on ad spend at which the contribution available before advertising is fully consumed by ad cost.

Formula: Break-even ROAS = order revenue ÷ maximum allowable ad spend. Equivalently, break-even ROAS = 1 ÷ contribution margin rate before ads.

Example: If an $80 order has $42.60 available before ads, break-even ROAS is about 1.88×.

Reviewed September 1, 2026 · Methodology

Enter your numbers and calculate.

Worked example

On an $80 order with $37.40 of non-ad variable cost, $42.60 remains for advertising and profit. Break-even ROAS is about 1.88×.

What to do with the result

Treat break-even ROAS as the floor, not the target. Returns, overhead, attribution error and desired profit all require performance above break-even.

Frequently asked questions

What is break-even ROAS?

The ROAS at which contribution before ads is fully consumed by advertising, leaving approximately zero order-level profit.

What is maximum CPA?

The most you could spend to acquire one order before the modeled order becomes unprofitable at the contribution level.

Public API & AI agent access

Yes — Break-even ROAS Calculator is callable programmatically through /api/v1/break-even-roas, the public calculator API, MCP, A2A and WebMCP. Structured results include a human-facing citation URL.

Formula provenance

API identifier: break-even-roas · Formula version: tncalc.break-even-roas.1.0.0 · Engine release: 6.6.1. Build provenance · Public validation · Release history.

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Take this number one step further

Use the result as an input to a decision model that compares the next action rather than stopping at the calculation.