Glossary

RPM against CPM

2 min read

RPM is revenue per mille: your earnings divided by every view, times a thousand. CPM is cost per mille: what advertisers paid, divided by monetised ad impressions, times a thousand.

They sound alike, they are quoted interchangeably, and they measure opposite sides of the same transaction.

The two differences that matter

RPM CPM
Denominator Every view Monetised ad impressions only
Numerator Your revenue, after the platform's share Advertiser spend, before it

Both differences push the same way, which is why CPM is always substantially higher than RPM on every channel.

The denominator. Not every view carries an ad. Viewers with ad blockers, viewers on Premium, videos that were not monetised, and plenty of ordinary playbacks produce no ad impression at all. The RPM denominator is therefore much larger than the CPM one.

The numerator. CPM is what the advertiser was billed. RPM is what reached you after the platform took its cut.

Why this matters practically

The most common mistake in creator revenue discussions is comparing your RPM against somebody's quoted CPM and concluding you are being underpaid.

You are comparing a post-revenue-share figure over all views against a pre-revenue-share figure over ad impressions. The gap is structural. It is not a sign of anything.

If you want to compare yourself to somebody, compare RPM to RPM. If you want to understand advertiser demand in your niche, CPM is the right number and your own revenue is not.

RPM is the one worth watching

Because it is the only one that answers "what is a view worth to me".

A rising CPM with a falling RPM means advertisers are paying more and fewer of your views are carrying ads, which is a format or audience change rather than a market one. A rising RPM is money.

RPM also moves for reasons that have nothing to do with ad rates: longer videos carry more ad slots, a different audience country changes rates entirely, and a shift towards Shorts usually lowers it sharply.

Compute it over the window

RPM is a ratio, so it has the same trap as every ratio.

Right:  (total_revenue / total_views) * 1000
Wrong:  mean(daily_revenue / daily_views * 1000)

A quiet day with one high-value view produces an enormous daily RPM and should contribute almost nothing to the period figure. Averaging the points weights it equally with a day of ten thousand views, and the result jumps around for no reason.

RPM in Notch Metrics

YouTube RPM is computed over the whole window rather than averaged across daily rates, which is how YouTube Studio reports it. The page says plainly that it is not CPM.

Place it beside estimated revenue, ad revenue and views.

How to read estimated revenue and RPM from YouTube Analytics

Questions

What is the difference between RPM and CPM?
RPM is your revenue after the platform's share, divided by every view. CPM is what advertisers paid before the platform's share, divided by monetised ad impressions only. Both differences push the same way, which is why CPM is always much higher.
Why is my RPM so much lower than CPM?
Because not every view carries an ad, so the RPM denominator is far larger, and because RPM is what reached you after the platform took its cut while CPM is what the advertiser was billed. The gap is structural, not a sign of anything wrong.
Which should I track, RPM or CPM?
RPM. It is the only one that answers what a view is worth to you. CPM is the right number for understanding advertiser demand in your niche, and it tells you nothing about your own earnings.
Why did my RPM drop without my CPM changing?
Usually a format or audience change rather than a market one. Shorter videos carry fewer ad slots, a shift towards Shorts lowers RPM sharply, and a change in audience country changes rates entirely.
How should RPM be calculated over a week?
Total revenue divided by total views, times a thousand. Not the average of the daily RPM values: a quiet day with one high-value view produces an enormous daily figure and should contribute almost nothing.