What this calculator does
CPM means cost per thousand impressions. It is a standard way to compare media cost for display, video, paid social, sponsorship and awareness campaigns.
Formula used
CPM equals total cost divided by impressions, multiplied by 1,000. Click-through rate equals clicks divided by impressions. Cost per click equals cost divided by clicks. Cost per conversion equals cost divided by conversions. Cost at a target CPM equals impressions divided by 1,000, multiplied by the target CPM.
How to read the result
A low CPM is not automatically better. Compare CPM with audience quality, placement, viewability, click-through rate, conversion rate, cost per conversion and downstream value.
Assumptions
- Uses served impressions, not viewable impressions.
- Does not include agency fees, platform fees, refunds or conversion value.
- Treats clicks and conversions as campaign actions from the same reporting period.
- Cost per conversion is shown only as a simple campaign average.
Sources and checks
This calculator uses a standard public formula. Where rules or thresholds can change, source links are listed on the relevant page.
Frequently asked questions
How do you calculate CPM?
Divide campaign cost by impressions, then multiply by 1,000. For example, GBP 500 spent on 100,000 impressions gives a GBP 5 CPM.
Why is CPM useful?
It puts campaigns with different budgets and impression volumes onto the same cost basis, making media prices easier to compare.
Can CPM be converted to CPC?
Yes, if you know click-through rate. This calculator uses actual cost, impressions and clicks, then shows the resulting CPC alongside CPM.