eCPM Calculator (Effective Cost Per Mille)
This calculator works out effective cost per mille, the revenue an ad placement earns for every 1,000 impressions. Pick whether you want to solve for eCPM, revenue or impressions, fill in the two values you know, and it returns the third. A currency selector formats the money side, and a breakdown line restates the result as revenue over impressions equals a figure per 1,000.
How to calculate eCPM
- Choose what to solve for in the Solve for menu: eCPM, Revenue or Impressions.
- Pick your currency from the second dropdown so figures format correctly.
- Enter the two values that stay visible, for example ad revenue and impressions.
- Read the highlighted result and the revenue over impressions breakdown beneath it.
- Click Copy to grab the solved figure for a report or spreadsheet.
Examples
eCPM from revenue and impressions
Solve for eCPM, $75 revenue, 25,000 impressions
$3.00 eCPM
Revenue from a target eCPM
Solve for Revenue, $8 eCPM, 50,000 impressions
$400.00 revenue
Impressions needed for a revenue goal
Solve for Impressions, $120 revenue, $5 eCPM
24,000 impressions
Frequently asked questions
What is the eCPM formula?
eCPM equals total ad revenue divided by impressions, then multiplied by 1,000. For example, $75 of revenue from 25,000 impressions works out to a $3.00 eCPM.
What is the difference between eCPM and CPM?
CPM is the rate an advertiser agrees to pay per 1,000 impressions on a single buy. eCPM is the effective revenue a publisher actually earns per 1,000 impressions across every source, including house ads and unfilled inventory, which is why it is the number publishers track.
How do I estimate revenue from an eCPM?
Set Solve for to Revenue, then enter your eCPM and expected impressions. The tool multiplies them and divides by 1,000, so an $8 eCPM over 50,000 impressions projects to $400.00.
How many impressions do I need to hit a revenue target?
Set Solve for to Impressions and enter your revenue goal and eCPM. To earn $120 at a $5 eCPM you would need 24,000 impressions, since revenue divided by eCPM times 1,000 gives the count.
How precise is the eCPM value?
The engine rounds eCPM to four decimal places, which the JSON API returns in full. The on-page figure is shown in your selected currency rounded to cents, so a raw 3.0488 eCPM displays as $3.05.
Can I use it for costs instead of revenue?
Yes. The same maths applies to an advertiser's spend. Enter cost in place of revenue and the eCPM becomes your effective cost per 1,000 impressions rather than earnings.
Does the currency choice change the maths?
No. The currency selector only controls how the numbers are formatted and which symbol is shown. eCPM is a ratio, so the calculation is identical whether you display dollars, euros or pounds.
What counts as an impression?
An impression is one served view of an ad. eCPM does not care whether a viewer clicked, so it measures monetisation of inventory rather than engagement, which click-through rate and cost per click track instead.
Is anything I enter stored?
No. Every calculation runs in your browser and nothing you type is uploaded or saved, so revenue figures stay private to your device.
Learn more
- eCPM, CPM and RPM: which ad metric to trust
How effective CPM differs from a plain CPM rate and from RPM, why publishers watch it closely, and what changes the number.
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