How to use the ad frequency cap calculator
This tool does not hand you a recommended frequency built from invented multipliers. An optimal cap cannot be derived without performance data by frequency, and the right level moves with vertical, price point, campaign objective, and creative rotation. So you supply impressions, conversions, and cost for each frequency band of your own campaign, and the calculator locates where marginal CPA turns.
Enter up to four bands, lowest frequency first. The table shows each band's band CPA (that band's cost รท that band's conversions, i.e. marginal CPA) beside the cumulative CPA through that band. The first band whose CPA rises above the band before it is where efficiency turns, and the band just before it becomes the cap candidate. Add a target CPA and the first band that breaks it is flagged separately.
A band with zero conversions cannot produce a CPA, so it is shown as such and treated as a worsening signal, since cost was spent with nothing returned. Copy the band boundaries straight from your platform's frequency report, and remember that short windows leave few conversions per band, which makes the turn point unstable.
Frequently asked questions
An optimal cap cannot be derived without performance data by frequency, and the right level shifts with vertical, price point, campaign objective, and how many creatives are in rotation. Rather than invent multipliers, this tool takes your own band-level results and locates where marginal CPA turns.
Band CPA is that band's own cost divided by that band's conversions, which is the marginal CPA. Cumulative CPA divides cost summed from the first band through the current one by the matching conversions. For cap decisions, the change in band CPA is the more direct signal.