Gross Rating Point (GRP)

A Gross Rating Point (GRP) is a measure of the total volume of advertising exposure delivered by a campaign within a target population, used mainly in television, radio, and out-of-home advertising.

GRP is calculated as reach% x frequency, where reach is the percentage of the target population exposed at least once and frequency is the average number of times each person was exposed. A campaign reaching 40% of an audience an average of three times delivers 120 GRPs. Because GRP multiplies reach and frequency together, the same total can come from very different combinations: broad reach with low frequency, or narrow reach with heavy repetition.

Media planners use GRPs to buy and compare advertising inventory, and to set frequency capping rules that avoid over-exposing the same viewers. GRP differs from audience measurement more broadly in that it is a single summary number derived from measurement data, not the measurement itself. Its main limitation is that it says nothing about attention or recall; a high GRP total does not guarantee the ad was watched or remembered, which is why it is increasingly paired with brand lift studies.