Advertising and publisher calculator
CPM Calculator
Calculate cost per thousand impressions (CPM or cost per mille), estimate impressions from a budget, or find the cost required for an impression goal. Publishers can use revenue to calculate eCPM.
CPM results
CPM means cost per mille, where mille means one thousand. Advertisers use CPM to express the average cost of 1,000 impressions. Publishers often use the same equation with revenue instead of cost and call the result effective CPM (eCPM).
CPM and eCPM formulas
CPM: CPM = cost ÷ impressions × 1,000
eCPM: eCPM = revenue ÷ impressions × 1,000
Estimated impressions: impressions = amount ÷ CPM × 1,000
Required cost or projected revenue: amount = impressions ÷ 1,000 × CPM
How to use the calculator
- Select advertiser or publisher perspective. The perspective changes labels, not the equation.
- Select CPM/eCPM, impressions or cost/revenue as the value to calculate.
- Choose a display currency and enter the two active values using one reporting period and scope.
- Select Calculate CPM. For impression planning, compare the theoretical result with the maximum whole impressions supported.
Verified examples
| Inputs | Calculation | Result |
|---|---|---|
| US$2,400 campaign cost and 800,000 impressions | 2,400 ÷ 800,000 × 1,000 | US$3 CPM; US$300 per 100,000 impressions |
| US$5,000 budget at US$4.25 CPM | 5,000 ÷ 4.25 × 1,000 | 1,176,470.59 theoretical impressions; 1,176,470 whole impressions |
| 250,000 impressions at €6.40 CPM | 250,000 ÷ 1,000 × 6.40 | €1,600 required cost |
| US$600 publisher revenue and 200,000 impressions | 600 ÷ 200,000 × 1,000 | US$3 eCPM |
How to interpret CPM
A lower advertiser CPM buys more impressions for the same modeled budget, but it does not prove that the impressions are viewable, relevant or profitable. A higher publisher eCPM means more revenue per 1,000 served impressions, but it does not by itself measure fill rate, total revenue or user experience.
CPM is based on impressions, not unique people. The same person may generate several impressions. Reach, frequency, clicks, conversions and revenue answer different questions and should not be treated as interchangeable.
Limits and assumptions
- Cost, budget or revenue must be greater than zero and no more than 1 trillion currency units.
- Recorded or desired impressions must be whole numbers from 1 to 1 trillion.
- Target CPM or eCPM must be greater than zero and no more than 1 billion currency units.
- Calculated monetary amounts and theoretical impressions are limited to 1 trillion.
- Currency selection changes formatting only and does not convert exchange rates.
- The calculator assumes a constant average CPM. It does not model auctions, pacing, frequency, viewability, invalid traffic, taxes, commissions, fill rate or platform adjustments.
Important: this is an educational advertising and publishing calculator, not a forecast or guarantee of reach, traffic, conversions, revenue or profitability.
Frequently asked questions
What does CPM stand for?
CPM stands for cost per mille, meaning cost per thousand. In advertising, it is the average cost for 1,000 impressions.
What is the difference between CPM and eCPM?
The equation is the same. Advertiser CPM usually uses campaign cost, while publisher eCPM uses earned revenue. Keeping the perspectives separate avoids treating a publisher’s revenue as an advertiser’s spend.
Is CPM the same as CPC?
No. CPM divides cost by impressions and scales the result to 1,000 impressions. CPC divides cost by clicks. A campaign can have a low CPM and a high CPC when few impressions produce clicks.
Are impressions the same as reach?
No. Impressions count displays or deliveries; reach usually estimates distinct people or accounts. Multiple impressions can come from one person.
Related calculators
- CPC Calculator — calculate cost per click, clicks from budget or required budget.
- CTR Calculator — calculate click-through rate, clicks or impressions.
- ROAS Calculator — compare attributed revenue with ad spend and estimate break-even ROAS.
- Percentage Calculator — calculate percentages, changes, increases and decreases.