# How to Calculate GRPs

Medioimages/Photodisc/Photodisc/Getty Images
Share It

GRPs are also known as gross rating points. These are a measure of the gross showing an advertising campaign has over a given time. This number does not determine the influence your ads have over people, but it merely relates how many were tuned to the station at the time your ad was airing. For further analysis of your marketing, you will need to look at GRPs with other ratings analysis systems.

Use the following formula to calculate your GRPs: Reach x Frequency = GRP. Reach is the number of individuals or homes who saw an ad at least once in your campaign schedule; frequency is the average number of times they saw it.

Add up your total reach, and then insert your reach data into the equation. Each percentage is equal to one rating point. For instance 1 percent of viewers = 1 point. If the every time you showed your commercial, 25 percent saw it and you aired it five times, then you would multiply 25 x 5 = 125. It is possible to get a number larger than 100.

Use the formula for each show or ad you have. Solve GRPs for commercials on two different channels. Ad A airs 3 times and gets 15 percent of viewers tune in. Ad B airs five times and gets 10 percent of viewers tune in.

Solve the total GRPs. You have to solve each individually then add the totals. Ad A GRP = 15 x 3 = 45. Ad B GRP = 5 x 10 = 50. To get the total GRPs add 45 + 50 = 95 GRPs.