What is ad frequency?
Ad frequency is the average number of times each person saw your ad. It pairs with reach, which counts how many unique people saw it at all, to describe how an impression budget was spent.
It is the simplest early warning for ad fatigue. The same creative shown too many times to the same people stops working and starts costing.
The formula.
Ad frequency = total impressions ÷ unique reach. Both numbers come straight from the ad platform's reporting.
The result is an average, so a frequency of 3 means the typical person saw the ad three times, while some saw it far more.
A worked example.
A campaign serves 90,000 impressions to 30,000 unique people. Frequency is 90,000 ÷ 30,000, which is 3.
What is a good ad frequency?
Up to about 3 per person suits most objectives, enough to be remembered without wearing thin. Between 3 and 7, watch for diminishing returns, especially on a single creative. Above 7, most campaigns are overexposed and spending on impressions that no longer move anyone. The right ceiling depends on the goal and the length of the campaign.
High frequency is wasted unless the extra exposure earns a response. Checking it against whether the extra impressions convert tells you if frequency is helping or just costing.
How to manage it.
Set a frequency cap, broaden the audience, and rotate creative so repeated exposure still feels fresh. Capping frequency often frees budget to reach new people.
Paid reach has to be rebought every time. An organic presence keeps reaching people so you can reach people without paying twice.