CPM Reach Calculator
Translate budget into impressions, then account for average frequency to estimate how many unique people may be reached.
Estimate unique reach
Convert a CPM-based budget into impressions, then account for repeat exposure with average frequency.
Symbols only; values are not converted.
Example values are prefilled—edit either available input.
i
The media amount available to purchase impressions.i
The amount paid for each 1,000 impressions.i
The average number of times each person sees the advertisement.How this calculation works
Reach requires a frequency assumption because one person can generate more than one impression.
Example calculation
A £2,000 budget at £5 CPM produces 400,000 impressions; at frequency 2.0, estimated reach is 200,000 people.
Change either input in the calculator to model a different campaign scenario.
Use the result correctly
- Use a frequency estimate appropriate to the channel and campaign length.
- Treat calculated reach as a planning estimate.
- Use platform-reported deduplicated reach after launch.
Frequently asked questions
What does cpm reach calculator calculate?
It calculates CPM, total cost, or impressions from any two known values. The page also explains the formula in the context of reach requires a frequency assumption because one person can generate more than one impression.
What formula does cpm reach calculator use?
Impressions = (budget ÷ CPM) × 1,000; estimated reach = impressions ÷ average frequency.
Is cpm reach calculator free to use?
Yes. The calculator runs in your browser and does not require an account.