This calculator computes Gross Rating Points (GRP) for media plans using either Reach (%) × Frequency or Impressions ÷ Audience Size. GRP summarizes campaign weight so you can compare plans and budget efficiently. Core fields include Reach (%), Frequency, Impressions, and Audience Size.
Introduction
GRP is the sum of rating points; 1 rating point = 1% of the target audience. The calculator supports two modes: Reach × Frequency and Impressions & Audience. In practice, GRP is equivalent to the percentage of the target audience delivered as total exposures. Formulas used:
How to Use the GRP Calculator
Use these steps to enter your data and read results correctly.
Select Method:
- Reach × Frequency if you know Reach (%) and Frequency.
- Impressions & Audience if you have total Impressions and Audience Size.
For Reach × Frequency: enter Reach (%) (0–100) and Frequency (can be decimal). The tool applies
Result shows GRP, with your Reach and Frequency echoed in Results.
For Impressions & Audience: enter total Impressions and the target Audience Size (people/households). The tool applies
Result shows GRP and echoes Impressions and Audience Size.
Use Show decimals to display fractional results (e.g., 182.5 GRPs) for more precise planning.
Sense-check the magnitude: TV and large digital plans often fall between 100–1000 GRPs; niche or short flights may be lower.
If you must back into a component, rearrange as needed (e.g., estimate Reach % by dividing GRP by Frequency, or find Impressions from GRP and Audience Size).
Record outputs from Results: GRP for plan weight; Reach/Frequency for distribution of exposures; Impressions/Audience Size for scale.
Frequently Asked Questions
What does GRP stand for?
GRP stands for Gross Rating Points. It measures the total exposure of an advertising campaign by multiplying reach and frequency.
How is GRP calculated?
GRP can be calculated using either:
- Reach × Frequency, where Reach is expressed as a percentage.
- (Impressions ÷ Audience Size) × 100, which converts impressions into rating points.
What does a GRP value indicate?
A GRP of 180, for example, means that the total audience exposure equals 180% of the target market. This could mean every person saw the ad 1.8 times on average, or 60% saw it three times.
Can GRP exceed 100?
Yes. GRP can exceed 100 because it counts duplicated exposures. It represents total impressions relative to the target audience, not unique reach.
What’s the difference between GRP, TRP, and Impressions?
GRP measures total exposure across all viewers, TRP (Target Rating Points) focuses on a specific demographic, and Impressions count total ad views, regardless of audience overlap.
Why are there two methods to calculate GRP?
The Reach × Frequency method is used when audience metrics are available, while the Impressions & Audience method is used when campaign delivery data is provided.
How do decimals affect GRP results?
Showing decimals increases precision. For instance, 62.5% reach × 3 frequency = 187.5 GRP, which may be rounded to 188 for reporting.
Gross Rating Points (GRP) quantify the total advertising weight delivered to a target audience. It is a key media planning metric that combines Reach (percentage of audience exposed) and Frequency (average number of exposures per person).
Modes Supported
- Reach × Frequency
- Impressions & Audience Size
Example 1
If 60% of the audience is reached 3 times:
Example 2
If 900,000 impressions are delivered to a 500,000-person audience:
Assumptions
- Reach is entered as a percentage (0–100).
- Frequency is a non-negative number.
- Audience size > 0 to avoid division by zero.
- GRP is not capped; values >100 are valid.
Edge Cases
- If audience size = 0, GRP is not defined.
- If reach = 0 or frequency = 0, GRP = 0.
- Decimals may be rounded to two places for reporting.
Rounding & Display
- Default rounding: 2 decimals.
- Intermediate steps retain full precision to minimize rounding error.
Sources & Methodology