CPM is the standard advertising-industry metric for the cost of 1,000 ad impressions.
How it works
Dividing total cost by impressions and multiplying by 1,000 gives CPM; multiplying a target CPM by impressions (divided by 1,000) gives the implied total cost.
What this does not include
This does not include click-through or conversion metrics — CPM measures impression cost only, not campaign performance beyond reach.
How to use this calculator
- Choose what to solve for, then enter the known values.
A worked example
A campaign costing $500 that delivers 200,000 impressions → CPM = (500 ÷ 200,000) × 1,000 = $2.50.
Given a $5 CPM and 100,000 impressions, total cost = (5 × 100,000) ÷ 1,000 = $500 — the reverse calculation.
What the variables mean
| Variable | Meaning |
|---|---|
| CPM | Cost per thousand (mille) impressions |
| Total cost | Total amount spent on the campaign |
| Impressions | Total number of ad views delivered |
Edge cases worth knowing
Zero impressions makes CPM undefined — there’s no delivered volume to spread the cost across.
CPM measures cost of reach, not cost of results. A campaign with a low CPM can still be inefficient if those impressions don’t convert — CPM alone says nothing about clicks or sales.
Frequently asked questions
What does “mille” mean in CPM?
It’s Latin for “thousand” — CPM stands for cost per thousand (mille) impressions.
Is a lower CPM always better?
Not necessarily — CPM measures cost efficiency of reach, but doesn’t account for how well those impressions convert into clicks or sales.
How is CPM different from CPC?
CPM charges per thousand impressions regardless of clicks; CPC (cost per click) charges only when someone actually clicks the ad.
