Understanding CPM
How we calculate. CPM = (spend ÷ impressions) × 1000. The form uses the same arithmetic as the worked examples on this page. See our methodology and accuracy policy.
Real-world scenario: A typical CPM case uses total cost 900 and impressions 300000. Enter the same figures below to reproduce the worked path.
What is CPM?
A reach-efficiency metric. Useful for comparing inventory costs when click volume is secondary to exposure.
- Mille = thousand
- Viewability definitions vary by network
- Compare like formats (video vs static)
The Formula
Worked Example
Common Use Cases
- Media plans: inventory cost checks
- Brand campaigns: awareness efficiency
- Vendor quotes: normalize proposals
Pro Tips
- Ask for viewable CPM when possible
- Frequency caps affect effective reach
- Don’t optimize CPM alone for performance goals
Limitations: CPM results are educational marketing planning aids—not guarantees of campaign performance. Platform definitions and attribution models vary.
FAQ
CPM vs CPC?
CPM prices impressions; CPC prices clicks. Choose based on campaign objective.
Can I solve for impressions?
Yes: impressions = (cost ÷ CPM) × 1000 when CPM is known.
Authoritative References
For advertising and analytics definitions, consult:
- Google Ads Help — CPC, CPM, conversion, and ROAS concepts
- IAB — digital advertising standards
- Google Analytics Help — conversion and engagement metrics