Google Review Rating Calculator

Google says your review score is the average of all ratings published on Google for your business. Add up all the stars, divide by the number of reviews, and you get the score. Google shows it with one decimal place. This calculator rounds to the nearest tenth, because Google doesn’t publish its exact rounding rule.

Two things to keep in mind:

• A shown 4.3 can be any average from 4.25 to just under 4.35. Two businesses with the same shown rating may be in very different spots.

• Google says it can take up to two weeks for the score to update after a new review.

Every new review is averaged with all the old ones, so the more reviews you have, the less one review moves the score. To reach a shown rating T, your average has to reach T − 0.05. If you have N reviews with an average of R, the number of new 5-star reviews you need is:

n ≥ N × (T − 0.05 − R) ÷ (5 − (T − 0.05)), rounded up to a whole review.

Example: 100 reviews averaging exactly 4.3, target 4.4. The average must reach 4.35, so n ≥ 100 × 0.05 ÷ 0.65 = 7.7, which means 8 more 5-star reviews.

The table shows the number of new 5-star reviews in a row, with the current average exactly at the starting value. Two patterns stand out:

• More reviews, slower moves. The count you need grows in proportion to the reviews you already have: five times the reviews, five times the work.

• The closer to 5, the harder. How far a 5-star review lifts the average depends on the gap between 5 and the current average. At 4.0 that gap is 1 star; at 4.8 it’s only 0.2, so climbing from 4.8 to 4.9 takes about six times as many reviews as climbing from 4.0 to 4.1.

It works the other way too. With 20 reviews averaging 4.8, a single 1-star review drops the average to (20 × 4.8 + 1) ÷ 21 = 4.62, shown as 4.6. With 100 reviews, the same review only moves you to 4.76, still shown as 4.8.

1. 1.

   Enter your numbers

   Copy the rating and review count from your Google Business Profile.

2. 2.

   Set a target

   For example 4.5 or 4.8.

3. 3.

   See how many you need

   The count assumes every new review is 5 stars, and uses Google’s rounding to one decimal.