GRP stands for Gross Ratings Points, and is used to measure a combination of reach and frequency of a particular ad campaign across the population corresponding to the marketer’s desired audience. It is often used as a measurement of legacy TV reach.
GRP is calculated using the following formula:
GRP = 100 * Reach (% of Target Audience) * Average Frequency
For example, if a marketer wishes to reach females 18-30, and executes a TV campaign that airs on 5 TV episodes for a TV show that reaches 30% of the target audience of females 18-30, then the GRP is 150 (i.e. 100 * 30% * 5).
