A clear result in a few inputs.
- Enter the requested values.Use consistent units and the real values for your scenario.
- Read the main result and breakdown.NumLuma recalculates immediately when an input changes.
- Check the formula and assumptions.Use the supporting context before making a real-world decision.
What this calculator does
CPM normalizes media cost to 1,000 impressions, making it useful for comparing the price of reach across campaigns. It does not tell you whether people clicked, converted or became profitable customers, so it should be paired with downstream metrics.
What to know before you use the result
- CPM uses impressions, not unique people reached.
- Use spend and impressions from the same scope and time period.
- Different placements and audiences can have very different CPMs even within the same ad platform.
Common mistakes to avoid
- Using reach instead of impressions in the CPM formula.
- Comparing CPM alone when one campaign is optimized for clicks and another for awareness.
- Mixing gross media spend with impression counts that exclude part of the campaign.
Where this calculation is useful
Display advertisingSocial media adsBrand campaignsMedia cost comparison
Related concepts
cost per milleimpressionsmedia buyingad reach