What is a gross rating point (GRP)?

How GRPs work

Reach × frequency = GRPs. A campaign reaching 40% of the population an average of three times delivers 120 GRPs.

The number exceeding 100 is not an error, and this catches people out. GRPs count exposures rather than people, so 120 GRPs means the equivalent of 120% of the population seeing the advertisement once — not that 120% of people were reached.

It is a measure of total advertising weight rather than of coverage.

GRP and TRP

GRPs are computed against a general population. Target rating points are computed against the specific audience a campaign is aimed at.

TRPs are almost always the more useful figure, because a campaign delivering large GRPs against a population that mostly cannot buy the product is delivering weight rather than value. Media plans quoting GRPs alone are usually describing scale rather than efficiency.

Why the concept still matters

GRPs came from a world where individual delivery could not be counted, so campaigns were planned in aggregate. Digital can count every impression, which made the metric look obsolete.

It survives because reach and frequency remain the right way to think about brand advertising, and because a single number combining them supports planning conversations that impression counts do not. Digital equivalents — reach and frequency reporting, and in some markets a digital GRP — exist for exactly that reason.

The framing also transfers usefully to newer surfaces. On AI media, where supply is scarce and one placement appears per conversation, reach and frequency thinking is more appropriate than impression volume — which is what conversational frequency caps are managing.