CPA room

Ecommerce CPA calculator guide

Break-even CPA is the most you can pay to acquire one order before that order loses money on the tracked variable costs.

What this means

CPA is often easier to manage inside ad platforms than ROAS. If current CPA is above break-even CPA, the product may lose money even when revenue is coming in.

Formula

breakEvenCpa = contributionMargin

For a target margin, subtract the target profit amount from contribution margin. If the remainder is zero or negative, target CPA is not available until costs or price improve.

Example

If contribution margin before ads is $19.92, break-even CPA is $19.92. Paying $24 CPA would lose about $4.08 per order before fixed overhead.

Common mistakes

  • Using average account CPA for every SKU.
  • Ignoring target margin when setting CPA caps.
  • Letting discounting reduce CPA room without updating targets.
  • Comparing CPA without refund and shipping impact.

Calculator

Switch the SellMira calculator to CPA mode to compare current CPA against break-even CPA.

Calculate break-even CPA