MonetrixRPM, CPM, eCPM, CTR and CPC explained
The five metrics behind every AdSense, AdMob and YouTube report — what they mean, how they’re calculated and which ones matter.
Ad platforms love acronyms. The good news is that almost all of them are variations on one idea: how much money per thousand of something. Here’s what each metric means and how to use it.
CPM — cost per mille
CPM is what advertisers pay per 1,000 ad impressions. “Mille” is Latin for thousand.
CPM = advertiser spend ÷ impressions × 1,000
On YouTube, the CPM in YouTube Studio is the average advertisers paid per 1,000 monetised playbacks, before YouTube takes its share. It tells you how valuable your audience is to advertisers — not how much you earn.
RPM — revenue per mille
RPM is what you earn per 1,000 units of traffic, after the platform’s share.
- AdSense page RPM = estimated earnings ÷ page views × 1,000
- YouTube RPM = total revenue ÷ total views × 1,000 (it counts all views, monetised or not, and includes other revenue such as memberships)
RPM is the single best number for comparing your own performance over time, because it reflects both how many ads are shown and how much they pay.
eCPM — effective CPM
eCPM is your earnings per 1,000 ad impressions. It’s the headline price metric in AdMob.
eCPM = estimated earnings ÷ impressions × 1,000
Example: an app that earns $42 from 15,000 impressions has an eCPM of $2.80.
CTR — click-through rate
CTR is the percentage of impressions (or page views) that resulted in a click.
CTR = clicks ÷ impressions × 100
A sudden CTR spike can be a warning sign of accidental or invalid clicks; a steady decline can mean ads are poorly placed or users have become blind to them.
CPC — cost per click
CPC is the average amount you earn per click.
CPC = estimated earnings ÷ clicks
CPC depends mostly on your niche and audience location. Finance, insurance and software topics typically attract higher CPCs than entertainment.
Putting it together
| Metric | Measures | Where you’ll see it |
|---|---|---|
| CPM | Advertiser price per 1,000 impressions | YouTube |
| RPM | Your earnings per 1,000 page views / views | AdSense, YouTube |
| eCPM | Your earnings per 1,000 impressions | AdMob |
| CTR | % of impressions that get a click | AdSense, AdMob |
| CPC | Average earnings per click | AdSense |
Diagnosing a revenue drop
Revenue = traffic × price. When earnings fall, check in this order:
- Traffic — page views, app users, ad requests or video views. Fewer visitors means fewer ads.
- Fill — in AdMob, a lower match rate means requests are going unfilled.
- Price — RPM, eCPM and CPC. These often dip at the start of each quarter and in January when advertiser budgets reset, and rise ahead of holiday shopping periods.
- Mix — a shift towards countries or formats that pay less.
Monetrix shows page views, impressions, clicks, CTR, CPC, ad requests and match rate next to your earnings for every period, which makes this kind of check quick on a phone.
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