Frequency Calculator
Each person saw your ad 3.8 times on average, comfortably below fatigue territory.
What is Frequency?
Ad frequency is the average number of times each person saw your ad, calculated as impressions divided by reach. 450,000 impressions across 120,000 people is a frequency of 3.8x.
It separates two numbers advertisers often confuse: reach is how many distinct people you touched, impressions is how many times the ad appeared. Frequency is the ratio between them.
A little repetition builds recall, but past a point it becomes ad fatigue: the same people see the ad too often, response drops, and cost per result climbs.
How to calculate Frequency
Frequency = Impressions ÷ Reach
- Total the impressions. Count how many times the ad was served over the campaign window.
- Find the reach. Take the number of unique people who saw it, not the impression count.
- Divide impressions by reach. Impressions divided by reach is your frequency. 450,000 ÷ 120,000 = 3.8x.
- Watch it against fatigue. Keep an eye on frequency as a campaign runs. Once it climbs past about 4x, check whether response is starting to slide.
Worked example
A campaign serves 450,000 impressions and reaches 120,000 unique people.
| Impressions | 450,000 |
|---|---|
| Reach (unique people) | 120,000 |
| Result | 3.8x frequency · healthy |
Each person saw the ad about 3.8 times on average, just under the common 4x fatigue ceiling. Enough to build recall without overexposing the audience, but close enough to the line to keep watching.
What is a good Frequency?
A widely used rule of thumb caps frequency at about 4x within a campaign window before fatigue sets in. It is a convention, and the right level depends on audience size and creative.
| Frequency | Read |
|---|---|
| Healthy 4x or below | Builds recall without overexposing the audience |
| Watch Above 4x | Fatigue risk: cost rises, response falls |
The 4x line is a guideline, not a law. A long flight, a small audience or strong creative can sustain higher frequency, while a short burst may fatigue sooner. Watch your response curve, not just the number.
How to improve Frequency
- Broaden the audience so the same impressions reach more people and frequency falls.
- Set a frequency cap in the platform to stop the same users being hit too often.
- Rotate in fresh creative regularly, which resets fatigue even at the same frequency.
- Track cost per result alongside frequency, since rising cost is the real signal that fatigue has set in.
Frequently asked questions
- What is ad frequency and how do you calculate it?
- Ad frequency is the average number of times each person saw your ad, calculated as impressions divided by reach. 450,000 impressions across 120,000 unique people is a frequency of 3.8x. It is the difference between how often the ad showed and how many people it actually reached.
- What is a good ad frequency?
- A common rule of thumb keeps frequency at or below about 4x within a campaign window before fatigue sets in: rising cost and falling response. Some repetition aids recall, so very low frequency is not automatically better. The right ceiling depends on campaign length, audience size and how distinct your creative is.
- Is a frequency of 3.8x good?
- A 3.8x frequency sits just under the common 4x fatigue threshold, so it reads as healthy: enough repetition to build recall without overexposing the audience. It is close to the ceiling, though, so it is worth watching whether response holds or starts to slide as it edges higher.
- How do I lower ad frequency without losing reach?
- Broaden the audience so the same impressions spread across more people, or add a frequency cap in the platform settings. Rotating in fresh creative also helps, since it resets fatigue even when the same people see the ad again. The aim is to keep building reach rather than re-hitting a small group.