eCPM is revenue per 1,000 impressions
AdMob Help defines eCPM as (total earnings / impressions) × 1000, an estimate of the revenue you receive for every thousand ad impressions. Estimated earnings in reports can still change, so the same day's eCPM may look slightly different a few days later.
Impressions are fewer than requests
The reports glossary separates match rate (requests that got an ad back) from show rate (returned ads that were actually displayed). When you estimate daily impressions, use how often an ad was actually shown, not how often you asked for one.
Official documentation (checked 2026-10-17)
FAQ
How is eCPM calculated?
Divide estimated earnings by impressions and multiply by 1,000. If 25,000 impressions earned $28.10, eCPM is $1.12. This matches AdMob Help's definition.
Can I use ad requests instead of impressions?
No. In the AdMob glossary, requests are counted even when no ad comes back, while impressions are ads actually shown to users. Using requests makes eCPM look lower than it is.
How accurate is the 30-day estimate?
It multiplies one day by 30, so use it for direction only. Real eCPM varies by country, ad format, season, and ad unit, and AdMob's estimated earnings can change before they're finalized.
Are the numbers I enter stored?
No. The calculation runs in your browser. Copy link puts your numbers and currency in the URL so the same calculation opens again from that link.
Checking eCPM app by app every day?
applog connects AdMob read-only and puts ad revenue, impressions, and revenue per 1,000 impressions on your home table per app, with revenue for the chosen period added up in KRW. It's free to use right now.