GRP Calculator
Results are estimates based on the values you enter. Recheck your inputs and assumptions before using the output for decisions.
Calculate gross rating points from reach, average frequency, and target audience size for media planning.
GRP Calculator
Free online GRP calculator to measure gross rating points from reach and average frequency for media planning and campaign analysis. This calculator is useful for media planners, ad buyers, brand managers, marketing teams, agencies, and students who need a quick way to estimate campaign weight. GRP stands for gross rating points, and it is one of the standard metrics used to describe the total exposure delivered by a campaign against a target audience.
This page uses three inputs: reach percentage, average frequency, and target audience size. Reach tells you what share of the target audience is exposed to the campaign at least once. Average frequency tells you how many times the reached audience is exposed on average. Target audience size helps convert the percentage metric into estimated people reached and total impressions. With those values, the calculator shows gross rating points, reached audience, gross impressions, and the average impressions per person reached. That makes the result useful for both percentage-based media planning and audience-based forecasting.
The formula of GRP
Gross rating points (GRP) = Reach (%) x Average frequency
Reached audience = Target audience size x Reach / 100
Gross impressions = Reached audience x Average frequency
Average impressions per person reached = Gross impressions / Reached audience
Here reach means the percentage of the target audience exposed at least once, average frequency means the average number of exposures among the reached audience, and target audience size means the total number of people in the selected audience. GRP is a cumulative campaign weight measure, so a GRP of 150 does not mean 150 percent of people were reached. It means the total exposure delivered is equal to 150 rating points.
Solved Example
Example 1: Find the GRP if campaign reach is 35%, average frequency is 4.2, and the target audience size is 500,000.
Solve: GRP = 35 x 4.2 = 147.00
Reached audience = 500000 x 35 / 100 = 175,000
Gross impressions = 175000 x 4.2 = 735,000
Average impressions per person reached = 735000 / 175000 = 4.20
Example 2: Find the result if reach is 50%, average frequency is 3.0, and the target audience is 800,000.
Solve: GRP = 50 x 3.0 = 150.00
Reached audience = 800000 x 50 / 100 = 400,000
Gross impressions = 400000 x 3.0 = 1,200,000
Average impressions per person reached = 1200000 / 400000 = 3.00
Example 3: Find the result if reach is 62%, average frequency is 5.5, and the target audience is 1,200,000.
Solve: GRP = 62 x 5.5 = 341.00
Reached audience = 1200000 x 62 / 100 = 744,000
Gross impressions = 744000 x 5.5 = 4,092,000
Average impressions per person reached = 4092000 / 744000 = 5.50
Table of GRP calculator
| Reach | Frequency | Audience Size | GRP | Reached Audience | Gross Impressions |
|---|---|---|---|---|---|
| 25% | 3.0 | 300,000 | 75.00 | 75,000 | 225,000 |
| 35% | 4.2 | 500,000 | 147.00 | 175,000 | 735,000 |
| 50% | 3.0 | 800,000 | 150.00 | 400,000 | 1,200,000 |
| 62% | 5.5 | 1,200,000 | 341.00 | 744,000 | 4,092,000 |
How to use this GRP calculator
Enter the campaign reach percentage in the proper input field. After that, enter the average frequency and then the total target audience size. Make sure these values describe the same campaign and the same audience definition. Then click the calculate button. The calculator will show gross rating points, reached audience, gross impressions, and average impressions per person reached in the result box.
This calculator is useful when comparing campaign schedules, setting media weight, reviewing channel mixes, and translating audience assumptions into a more practical exposure forecast. A higher GRP usually means the campaign is delivering more total exposure, either by reaching more people, showing ads more often, or both. Looking at GRP together with reached audience and gross impressions makes it easier to understand whether weight is coming from broad reach or heavier frequency.
When using the result, remember that GRP is a summary planning metric, not a direct measure of persuasion or business outcome. Two campaigns can have the same GRP but very different performance depending on creative quality, timing, audience fit, and media environment. Even so, GRP remains a widely used way to compare media schedules and campaign pressure. This calculator gives a fast, clear estimate that supports media planning, presentation work, budget discussions, and exposure analysis.