What is CPM (Cost per mille)?

CPM is one of the most confusingly-named metrics in advertising. Many people assume that mille is short for million, but it’s actually Latin for thousand. So really, CPM = cost per thousand impressions.

Last updated 2026-04-17

CPM is one of the most confusingly-named metrics in advertising. Many people assume that mille is short for million, but it’s actually Latin for thousand. So really, CPM = cost per thousand impressions.

Remember, Meta’s CPMs are based on total impressions not unique viewers. So it’s not cost per thousand people seeing your ad, it’s cost per thousand times your ad is shown to someone.

Frequently Asked Questions

What is CPM (Cost per mille)?

CPM is one of the most confusingly-named metrics in advertising. Many people assume that mille is short for million, but it’s actually Latin for thousand. So really, CPM = cost per thousand impressions.