CPM Calculator
Enter what you spent and how many impressions you got to see the cost per thousand impressions. Add clicks to get the cost per click and click-through rate too.
How to use this CPM Calculator
- Enter the total you spent on the ad campaign.
- Enter the number of impressions the ads received.
- Add clicks if you want the cost per click and click-through rate.
- Enter a planned number of impressions to see what that reach would cost at the same CPM.
- Press Calculate and compare it across campaigns.
How to calculate CPM
CPM is the cost of reaching a thousand impressions.
- CPM = ad spend / impressions x 1,000
- CPC = ad spend / clicks
- CTR = clicks / impressions x 100
- Cost of planned reach = CPM x planned impressions / 1,000
Worked example
You spend $500 and your ads are shown 100,000 times. The CPM is 500 / 100,000 x 1,000 = $5.00. That is 200 impressions per dollar. With 1,000 clicks the cost per click is $0.50 and the click-through rate is 1.00%. If you plan to reach 500,000 impressions at the same CPM, the cost would be $2,500.00.
CPM is useful for awareness campaigns, where the goal is reach. For sales campaigns, CPC and cost per sale matter more. A low CPM is not always good, since cheap impressions can come from placements nobody notices. Use CPM to compare audiences and formats, and check what follows from it, such as clicks and conversions. When you plan a budget, use recent CPMs from the same platform and season, because prices rise in busy periods. Keep a simple log of CPM by month and by audience, so you can spot when costs climb and decide whether to pause, change the creative or shift budget to a cheaper placement.
Assumptions & limits
- The CPM is calculated from the spend and impressions you enter. Platforms may bill on different bases such as clicks or views.
- The cost of planned reach assumes the CPM stays the same as you scale. In practice it often rises as you reach more people.
- Impressions are counted the way your platform counts them, which differs between platforms.
- The calculator does not include creative or agency costs.
- It does not tell you whether the audience is the right one.
Frequently asked questions
How do I calculate CPM?
Divide the cost by the impressions and multiply by 1,000. $500 over 100,000 impressions is a $5.00 CPM.
What does CPM stand for?
It stands for cost per mille, which means cost per thousand impressions.
What is the difference between CPM and CPC?
CPM is the cost per thousand impressions. CPC is the cost per click.
Is a lower CPM better?
Not always. A low CPM can mean low-quality placements. Check clicks and conversions as well.
Why does CPM change?
Audience, season, competition, format and the platform all change it.
Can I use CPM to plan a budget?
Yes, but use recent CPMs from the same platform and expect the cost to rise as you scale.
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Last updated: November 2026