"One GRP is one percent of all potential adult television viewers (or in radio, listeners) in a market." If they are exposed to the ad three times, then that is 3 GRPs. GRPs are simply total impressions related to the size of the target population: They are most directly calculated by summing the ratings of individual ads in a campaign. Mathematically: ::GRPs (%) = 100 * Total Impressions (#) ÷ Defined population (#) ::GRPs (%) = 100 * Reach (%) × Average frequency (#) Three examples: • If 100,000 ad impressions are displayed on multiple episodes or TV stations for a defined population of 100,000 people, the total is 100 GRPs. However, total
reach is not always 100%. • If an average of 12% of the people view each episode of a television program, and an ad is placed on 5 episodes, then the campaign has 12 × 5 = 60 GRPs. • If 50% view three episodes, that's 150 GRPs. == See also ==