Reverse CPM Calculator
Back-calc CPM from cost and impressions or estimate cost from CPM. Add range checks and copy a clean summary—free, no signup.
Impressions definition checklist
Reverse CPM is only meaningful when impressions are defined consistently. Confirm billing definitions before you compare.
Counted when an ad is delivered by the server, regardless of viewability.
Definition: served
Counted only when viewability standards are met (e.g., 50% pixels for 1s).
Definition: viewable
Make-goods, under-delivery, or bonuses can skew effective CPMs in invoices.
Check: billing rules
Reverse CPM from cost and impressions, or estimate cost from CPM. Add range checks and copy a shareable summary.
CPM range (optional)
Use a range to flag when CPM is unusually high or low.
Result
US$12.50
CPM
Range check
No range set
Add a CPM range to get a status.
Summary
Copy this block into a brief, doc, or email.
Reverse CPM Calculator summary Mode: CPM from cost Cost ($): US$2,500.00 Impressions: 200,000 CPM: US$12.50 Formula: CPM = (Cost ÷ Impressions) × 1,000 Assumptions: impressions may be served or viewable depending on billing; CPM can vary by placement, geo, and time window.
Formula
CPM = (Cost ÷ Impressions) × 1,000
Interpret reverse CPM results with reconciliation tips and next-step checks. AI does not change the calculations.
Avoid sharing sensitive data. Insights are advisory only.
Use these references to confirm CPM definitions and formulas.
Keep normalizing media metrics with these tools.
Why this reverse CPM calculator is different
Reverse-first flow
Start with cost + impressions to back-calc CPM for reconciliation.
Range signal
Add an expected CPM range and flag when your result drifts.
Copy-ready summary
Share inputs, outputs, and assumptions in a clean block.
Optional AI insights
Get interpretation and next-step checks without changing the math.
How it works
Pick a mode
Reverse CPM from cost + impressions or estimate cost from CPM + impressions.
Enter the known values
Provide cost and impressions (or CPM and impressions) to calculate the missing output.
Validate and share
Add a CPM range, note impression definitions, and copy the summary.
FAQ
Reconcile CPM in seconds
Back-calc CPM, sanity-check with ranges, and share the summary.
Start calculatingEstimates only. Reverse CPM is only meaningful when impression definitions and billing rules are consistent.