What this calculator does
Reach is the number of unique people who saw a campaign; frequency is the average number of times each of them saw it. The two multiply together to give total impressions, so knowing any two of the three figures gives you the third.
A campaign can deliver the same number of impressions in very different ways: reaching a large audience once each, or a smaller audience many times each. Which is preferable depends on the goal, since brand awareness often benefits from repetition, while a broad, one-off message favours reach.
The formula
Frequency is total impressions divided by reach, and reach is total impressions divided by frequency. This calculator solves for whichever one you do not already know, given the impression total and the other figure.
| Term | Meaning |
|---|---|
| Reach | The number of unique people who saw the ad at least once. |
| Frequency | The average number of times each person in the reached audience saw the ad. |
| Impressions | Total ad views, equal to reach × frequency. |
The inputs explained
| Field | What to enter |
|---|---|
| Total impressions | The total number of impressions delivered by the campaign. |
| Solve for | Choose from Reach (known frequency), Frequency (known reach). |
| Known value (frequency if solving reach; reach if solving frequency) | Enter the frequency if solving for reach, or the reach if solving for frequency. |
When to use it
Planning a brand-awareness campaign
A target frequency, such as 3 to 5 views per person, is a common planning input; this calculator turns that target and an impression budget into an estimated reach.
Checking for ad fatigue
A rising frequency against a flat reach means the same people are seeing the ad more often rather than the campaign finding new audiences, which is worth knowing before creative fatigue sets in.
Comparing campaigns of different sizes
Two campaigns with the same total impressions can have very different reach and frequency profiles; separating the two numbers shows which strategy each one actually used.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How estimated reach changes with frequency at a fixed impression total
A fixed 500,000 impressions, across a range of average frequencies.
| Average frequency | Estimated reach (unique people) |
|---|---|
| 1× | 500,000 |
| 2× | 250,000 |
| 3× | 166,667 |
| 5× | 100,000 |
| 8× | 62,500 |
| 10× | 50,000 |
Questions
Why is my reach figure only an estimate?
Reach and frequency reported by ad platforms are themselves modelled estimates in most cases, since exact unique-person counts are rarely available. This calculator works from whichever two figures you supply, so its accuracy depends on theirs.
What frequency should I target?
It depends on the campaign goal and how memorable the creative is; there is no single correct number. Track how results change as frequency rises to find a level that works for a specific campaign, rather than adopting a fixed target.
Can frequency be less than 1?
No. Frequency is impressions divided by reach, and reach can never exceed impressions, so frequency has a minimum of 1 (each reached person seen at least once).
How does frequency relate to ad fatigue?
As frequency climbs, each additional exposure to the same person tends to add less impact, and can eventually turn negative if the audience starts to find the ad repetitive or irritating.
To see the cost of the impressions behind these reach and frequency figures, use the CPM calculator.