CPM Calculator

Calculate advertising cost per thousand impressions

Your result will appear here.

About the CPM Calculator

CPM measures advertising cost per one thousand impressions. It is commonly used for display, video and awareness campaigns where the buying unit is exposure rather than a click or conversion.

CPM says nothing about whether viewers clicked, bought or remembered the ad. It should therefore be interpreted alongside engagement and conversion metrics.

How to Use the CPM Calculator

  1. Enter total advertising spend.
  2. Enter total impressions delivered.
  3. Calculate CPM.
  4. Use the same impression definition and reporting period when comparing campaigns or platforms.

How the Calculation Works

CPM = advertising cost ÷ impressions × 1,000. Dividing spend by total impressions gives cost per single impression, and multiplying by 1,000 expresses that small unit cost in the standard cost-per-thousand format.

The calculation assumes spend and impressions come from the same campaign, placement and reporting period. CPM measures the price of exposure only; it does not incorporate clicks, conversions, viewability or whether the impressions reached unique users.

Worked example

CPM Calculator Worked Example

$2,500 spent for 500,000 impressions

CPM = $2,500÷500,000×1,000 = $5.00.

Result guide

Understanding Your CPM Calculator Result

A lower CPM means cheaper exposure, but cheaper impressions are not necessarily more valuable if the audience is poorly matched or low quality. Viewability also matters for display advertising. An impression counted by the platform may not mean the user actually had a meaningful opportunity to see the ad, so a cheap CPM with weak viewability can overstate media efficiency.

Before you rely on the answer

Assumptions and Limitations

  • Spend and impressions refer to the same campaign and period.
  • Impressions are measured consistently across comparisons.
  • Clicks, conversions and viewability are outside the CPM calculation.

Practical tip

Using This Result in Practice

When comparing platforms, pair CPM with click-through rate or conversion rate. A more expensive CPM can still be better value if the audience responds much more strongly. For awareness campaigns, also review reach and frequency. A low CPM can be created by repeatedly serving inexpensive impressions to the same users, which may not expand the audience as much as the headline impression count suggests.

Related calculations

Useful Calculations to Continue With

If you want to see how often impressions produced clicks, use the Click-Through Rate Calculator.

If the buying question is cost per click rather than cost per thousand impressions, use the CPC Calculator.

Common questions

CPM Calculator FAQ

What does CPM stand for?

Cost per mille, meaning cost per one thousand impressions.

Is a low CPM always good?

No. Low-cost impressions can be poor quality or poorly targeted.

How is CPM different from CPC?

CPM prices exposure per thousand impressions; CPC measures spend per click.