# What is my CPM?

Computes CPM (the cost per 1,000 ad impressions) from the campaign cost and impressions, or the cost or the impressions from the other two.

- Page: https://www.acalculator.org/finance/cpm-calculator
- JSON spec: https://www.acalculator.org/finance/cpm-calculator.json
- Version: 47d2d60501ee

## Default answer

Example with the default inputs (Campaign cost $500.00, Impressions 50,000): Paying $500.00 for 50,000 impressions is a CPM of $10.00.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| cost | Campaign cost | What the ads cost in total. |
| impressions | Impressions | How many times the ads were shown. |
| cpm | CPM | The cost per 1,000 impressions: cost ÷ impressions × 1,000. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| cost | Campaign cost | What the ads cost in total. |
| impressions | Impressions | How many times the ads were shown, to the nearest whole impression (halves up). |
| cpm | CPM | The cost per 1,000 impressions: cost ÷ impressions × 1,000. |

## Method

CPM = cost ÷ impressions × 1,000; cost = CPM × impressions ÷ 1,000; impressions = cost ÷ CPM × 1,000.

## Assumptions

- Every impression costs the same: the CPM is an average over the campaign.
- Arithmetic is exact on the typed decimals; money shows to the cent and impressions to the whole number, halves up.

## Worked examples

1. cost = $15,000.00, impressions = 2,400,000 gives cpm = $6.25. Source: Wikipedia, "Cost per mille" (https://en.wikipedia.org/wiki/Cost_per_mille): 15,000 ÷ 2,400,000 = 0.00625.
2. cpm = $6.25, impressions = 2,400,000 gives cost = $15,000.00. Source: Wikipedia, "Cost per mille" (https://en.wikipedia.org/wiki/Cost_per_mille), worked back: 6.25 × 2,400,000 ÷ 1,000 = 15,000.
3. cost = $15,000.00, cpm = $6.25 gives impressions = 2,400,000. Source: Wikipedia, "Cost per mille" (https://en.wikipedia.org/wiki/Cost_per_mille), worked back: 15,000 ÷ 6.25 × 1,000 = 2,400,000.
4. cost = $1,000.00, impressions = 30,000 gives cpm = $33.33.

## FAQ

### What does CPM mean?

CPM is the cost per mille, the price of 1,000 ad impressions. Mille is Latin for thousand, and the M in CPM is the Roman numeral for 1,000. An impression is one showing of an ad.

### How do I calculate CPM?

Divide the total cost by the number of impressions and multiply by 1,000. A $15,000 campaign with 2,400,000 impressions has a CPM of 15,000 ÷ 2,400,000 × 1,000 = $6.25.

### How many impressions will my budget buy?

Divide the budget by the CPM and multiply by 1,000. $500 at a $10 CPM buys 500 ÷ 10 × 1,000 = 50,000 impressions.

### How much will a number of impressions cost?

Multiply the CPM by the impressions and divide by 1,000. 100,000 impressions at a $12 CPM cost 12 × 100,000 ÷ 1,000 = $1,200.

### What is the difference between CPM and CPC?

CPM is what you pay for 1,000 showings of an ad, whether or not anyone clicks. CPC (cost per click) is what you pay for each click. Divide the cost by the clicks for CPC.

### Is CPM the same as RPM?

No. CPM is what an advertiser pays per 1,000 impressions. RPM (revenue per mille) is what a publisher or creator earns per 1,000 views after the platform’s share. The YouTube money calculator uses RPM.

## Sources

- Wikipedia, "Cost per mille": formula and worked example ($15,000 for 2,400,000 impressions is a $6.25 CPM). https://en.wikipedia.org/wiki/Cost_per_mille
- Google Ads Help, "Cost-per-thousand impressions (CPM): Definition". https://support.google.com/google-ads/answer/6310