The two questions the two numbers answer
| CPM | RPM | |
|---|---|---|
| Question | What do advertisers pay? | What do I keep? |
| Denominator | 1,000 monetized playbacks | 1,000 total views |
| Revenue share | Before YouTube's cut | After YouTube's cut |
| Revenue scope | Ads only | Ads plus Premium, Supers, memberships, Shopping |
Both definitions are YouTube's own YouTube Help2026-08. CPM is a buy-side price on the subset of views that carried ads. RPM spreads your entire post-cut income across every view, monetized or not.
Why RPM is always lower, worked
100,000 views; 60,000 monetized playbacks; advertiser spend at $10.00 CPM
ad revenue gross = 60 × $10.00 = $600
your ad share (illustrative 55%) = $330; plus $70 Premium and Supers = $400 kept
RPM = 400 ÷ 100,000 × 1,000 = $4.00 vs the $10.00 CPM shown
Two compressions did that: the denominator grew from 60,000 to 100,000, and the revenue share shrank the numerator. The 55% figure above is a worked illustration, not a quoted rate; YouTube's standard ad revenue split for long-form partner content is stated in its Partner Program terms YouTube Help2026-08, and it varies by format. Non-ad revenue partially refills the numerator, which is why channels with strong memberships can show RPM closer to CPM than ad-only channels.
Which one to optimize
Steer by RPM. It is the only number in the pair denominated in money you receive, and it rewards everything that CPM ignores: raising the monetized share of views, adding non-ad revenue streams, and holding viewers in markets advertisers want. Watch CPM as a diagnostic: a falling CPM with stable RPM means your non-ad streams are carrying more of the load. The levers for both live on how to increase RPM.