Break-Even ROAS Calculator

The minimum return on ad spend your product economics can support.

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About this calculator

Before setting a ROAS target in your ad platform, you need the break-even point that falls out of your product economics: price, landed cost and fees determine the contribution per sale, and its inverse is the minimum ROAS. Below that number every "successful" campaign quietly loses money.

The formula

Contribution = Price − Cost − Fees Break-even ROAS = Price ÷ Contribution

Worked example

Price £30, cost £10, fees £5 → contribution £15 (50%). Break-even ROAS = 30 ÷ 15 = 2.0x.

Common mistakes

  • Setting a platform ROAS target below your break-even — scale just accelerates the loss.
  • Computing it from gross margin without fees and fulfilment.
  • Using revenue including VAT, which understates the true break-even.

Frequently asked questions

Many sellers target 1.3–2× their break-even ROAS so ads fund overheads and profit, not just product cost.

Yes — a 50% contribution margin means 2.0x, 25% means 4.0x. Thin-margin products need spectacular ad performance.

No — it's first-order maths. If customers reliably reorder, you can afford to run at or below first-order break-even deliberately.

Assumptions & limitations

First-order economics with constant per-unit cost and fees.

Sources & verification

This calculator applies the standard formula published above to the figures you enter — it relies on no external statutory data. The formula and the worked example were checked by hand against each other.

Formula last verified: 24 July 2026
Maintained by: Steve Davis, Founder & Editor — see our editorial standards

Spotted an error or an out-of-date figure? Report it — corrections are prioritised over all other work (see our corrections policy).

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