Gross rating point

Also known as: GRP

Gross Rating Point (GRP) is a unit to express the reach of an advertisement or advertising campaign. It takes into account both the reach (as a percentage of the total audience) and the frequency(impressions per visitor/viewer/listener) of the advertisement.

GRPs are used as a unit of account for advertising on TV, radio and the Internet, among other things, to compare providers and channels and to analyze campaigns.

Gross Rating Point calculation

Two different formulas can be used to calculate the number of Gross Rating Points:

GRP = Impressions (number) / Total audience (number)
or
GRP = Reach (percentage) × Average frequency (number)

If an advertising spot is broadcast six times around a television program with a viewing rate of 24%, this results in 144 GRPs. It is also said in this case that the reach is 144%, since one GRP corresponds to 1% viewing or listening density.

Compare GRP

The effective GRP can be calculated after the fact, or determined in advance when scheduling advertising. Television stations and radio stations often present a rate per GRP, derived from viewer ratings or listener ratings. Based on the intended reach and repetition, this makes it fairly easy to compare the costs of the various stations.