# CPM (cost per mille)

> CPM is what you pay for 1,000 ad impressions.

Canonical: https://use-addy.site/glossary/cpm
Last updated: 2026-10-26

Also called: cost per thousand impressions

**Formula:** CPM = ad spend ÷ impressions × 1,000

**Example:** $500 spent for 62,500 impressions is a CPM of $8.

CPM is set by the auction: competition for your audience, the time of year and how engaging the platform judges your ad to be. It usually rises in Q4. A better ad can lower CPM because platforms reward ads people watch, which is one reason creative quality affects cost and not just conversion.

## Related

- [CPM calculator](https://use-addy.site/tools/cpm-calculator)
- [CPC (cost per click)](https://use-addy.site/glossary/cpc)
- [CTR (click-through rate)](https://use-addy.site/glossary/ctr)
- [CPA (cost per acquisition)](https://use-addy.site/glossary/cpa)
- [Frequency](https://use-addy.site/glossary/frequency)