Break-even CPM Calculator

Compute break-even and target CPM from CTR, CVR, AOV, and contribution margin assumptions.

If you buy impressions (CPM), you need to know how much you can pay per 1,000 impressions and still break even.

This calculator converts CTR and CVR into expected conversions per 1,000 impressions, then computes the break-even CPM and a target CPM with buffer.

Prefer an explanation- Read the guide.
 
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Tip: you can type commas (e.g., 10,000).

Example

Using the default inputs, the result is:
$9.60
CTR
1.5%
CVR (click -> conversion)
2.5%
AOV
$80
Contribution margin
40%
Profit buffer
20%

How to calculate

  1. Enter CTR and CVR to estimate conversions per 1,000 impressions.
  2. Enter AOV and contribution margin to estimate contribution per conversion.
  3. Add a buffer to compute a target CPM below break-even.

Formula

Conversions/1000 = 1000xCTRxCVR; Break-even CPM = conversions/1000 x (AOVxmargin); Target CPM = break-even x (1-buffer)
  • CVR is click-based (conversions / clicks).
  • Contribution margin captures variable costs (not fixed overhead).
  • Ignores long-term LTV; best for one-time purchase economics.

FAQ

How is this different from max CPC-
Max CPC tells you what you can pay per click. Break-even CPM tells you what you can pay per 1,000 impressions. They are linked via CTR: CPM ~ CPCxCTRx1000.
What if my platform charges CPM but optimizes for conversions-
You can still use this as a sanity check, but ensure CTR and CVR reflect observed performance for that campaign and placement mix.

Common mistakes

  • Using mismatched denominators (session CVR vs click CVR).
  • Overstating margin by ignoring returns, shipping, and fees.
  • Assuming CPM buying is profitable without incrementality validation.

Quick checks

  • Keep attribution model and window consistent when comparing campaigns.
  • Pair efficiency metrics (ROAS/CPA) with profit assumptions (margin, refunds, fees).
  • Validate tracking after site changes (pixels/events can silently break).