eCPM Calculator
(Effective CPM Tool)
Work out eCPM from ad revenue and impressions. Switch modes to estimate revenue or the impressions a revenue goal needs.
Step 1 — Calculation Goal
What would you like to calculate?
Step 2 — Core Metrics
Total revenue earned from ads in the period
Total number of ad impressions delivered
eCPM Result
💡 Formula Guide
This eCPM calculator works out effective CPM, the amount a publisher earns for every thousand ad impressions. Enter ad revenue and impressions to get the eCPM, or turn it round: give it an eCPM and an impression count to estimate revenue, or an eCPM and a revenue goal to find the impressions needed. Add ad requests and it shows the fill rate too.
How to Calculate eCPM
eCPM is total earnings divided by total impressions, multiplied by 1,000. This is the formula Google gives in its AdMob help.
An app that earned $250 from 100,000 impressions has an eCPM of $250 ÷ 100,000 × 1,000 = $2.50.
| To find | Formula | Example |
|---|---|---|
| eCPM | Earnings ÷ Impressions × 1,000 | $250 ÷ 100,000 × 1,000 = $2.50 |
| Revenue | eCPM × Impressions ÷ 1,000 | $2.50 × 400,000 ÷ 1,000 = $1,000 |
| Impressions | Revenue ÷ eCPM × 1,000 | $500 ÷ $2.50 × 1,000 = 200,000 |
eCPM vs CPM
CPM is a price. An advertiser agrees to pay a set amount for a thousand impressions. eCPM is a result. It takes whatever a publisher earned, from ads sold by the impression, the click or the install, and expresses it per thousand impressions so that different deals can be compared.
| Campaign on 100,000 impressions | Earnings | eCPM |
|---|---|---|
| Sold at a $2.50 CPM | $250 | $2.50 |
| Paid $0.40 per click, 500 clicks | $200 | $2.00 |
| Paid $15 per install, 20 installs | $300 | $3.00 |
The install campaign pays best here even though it has no CPM at all. To work from the advertiser's side, use the CPM Calculator.
eCPM and Page RPM
Website reports often show RPM in place of eCPM. The formula is the same, but page RPM divides earnings by page views, not by ad impressions. A site that earns $6 from 1,000 page views with three ads on each page has a page RPM of $6 and an eCPM of $2, because those 1,000 page views produced 3,000 impressions. When you compare two figures, check which base each one uses. The AdSense Revenue Calculator estimates earnings from page views.
Fill Rate and eCPM Together
Fill rate is the share of ad requests that were answered with an ad.
An app that sent 120,000 requests and served 100,000 impressions has a fill rate of 83.3%. eCPM counts only the impressions that were served, so a high eCPM with a low fill rate can earn less than a modest eCPM that fills nearly every request.
| Network | eCPM | Fill rate | Earnings per 1,000 requests |
|---|---|---|---|
| A | $4.00 | 50% | $2.00 |
| B | $2.50 | 95% | $2.38 |
Network B earns more from the same traffic. Multiply eCPM by fill rate to compare ad sources fairly.
What Changes eCPM
- Ad format: full-screen and video formats are normally paid more per impression than small banners, because advertisers bid more for them.
- Audience country: advertisers pay different amounts to reach people in different countries, so the same app earns a different eCPM in each.
- Season: advertising budgets rise before major shopping periods and drop afterwards.
- Number of ads: adding more ads to a screen raises impressions but can lower the eCPM of each one. Judge the change by total earnings.
How to Use the eCPM Calculator
- Choose what to solve for: Pick eCPM, expected revenue or required impressions.
- Enter the two known values: Type in two of ad revenue, impressions and eCPM. The third is calculated as you type.
- Add ad requests: Optional. Open the fill rate settings and enter total ad requests to see what share of them were filled.
Frequently Asked Questions
How do I calculate eCPM?
Divide total ad earnings by total impressions and multiply by 1,000. An app that earned $250 from 100,000 impressions has an eCPM of $250 ÷ 100,000 × 1,000 = $2.50.
What does eCPM stand for?
Effective cost per mille, where mille is Latin for thousand. Google's AdMob help describes it as an estimate of the revenue you receive for every thousand ad impressions.
What is the difference between CPM and eCPM?
CPM is a price an advertiser agrees to pay for a thousand impressions. eCPM is what a publisher actually earned per thousand impressions once every kind of ad is counted, including ads paid per click or per install. The arithmetic is the same; the point of view is different.
Is eCPM the same as RPM?
They use the same formula with a different base. eCPM divides earnings by ad impressions. Page RPM divides earnings by page views. A page with three ads counts three impressions for one page view, so its page RPM is three times its eCPM.
What is a good eCPM?
There is no single figure. eCPM depends on the ad format, the country of the audience, the season and the app or site category, and the ad networks do not publish one shared average. Compare your eCPM with your own earlier periods and across formats and countries in your own reports.
Why did my eCPM go up while my revenue went down?
eCPM only measures the impressions that were served. If fewer ad requests are filled, the remaining impressions can be the better-paid ones, so eCPM rises while total earnings fall. Check fill rate and impressions beside eCPM.
The eCPM definition and formula were checked against Google's AdMob help in October 2026.