Your Google star rating looks like a simple number, but it hides a lot. Two businesses can both show 4.8, while one is a single review away from 4.9 and the other is dozens of reviews away. The difference is in the maths, and in how Google rounds it.
This guide shows exactly how Google works out your rating, how the rounding works, and how long changes take to appear. There's also a free calculator, so you can see your exact average and how many 5-star reviews it takes to reach the next step.
Quick answer: Google says your review score is "the average of all ratings published on Google" for your business. Multiply each star level by how many reviews you have at that level, add them up, and divide by your total number of reviews. Google then shows the result to one decimal place, so an exact average of 4.85 or more shows as 4.9, and 4.849 shows as 4.8.
How Google calculates your star rating
Every rating on your Google Business Profile counts, including star-only ratings with no written review. To work out your average:
- Multiply each star level by the number of reviews at that level. For example, 100 five-star reviews is worth 500 points.
- Add the points from all five star levels together.
- Divide the total points by your total number of reviews.
That's your exact average. Google then rounds it to one decimal place, and that's the rating people see in Search and Maps.
A worked example
Here's a business with 3,050 Google reviews:
| Star level | Reviews | Points |
|---|---|---|
| 5 stars | 2,811 | 14,055 |
| 4 stars | 128 | 512 |
| 3 stars | 43 | 129 |
| 2 stars | 27 | 54 |
| 1 star | 41 | 41 |
| Total | 3,050 | 14,791 |
14,791 points divided by 3,050 reviews is 4.8495. Google shows that as 4.8.
Here's the catch. If you put these numbers in a spreadsheet set to three decimal places, it shows 4.850, which looks like it should round up to 4.9. It doesn't, because the real average is just under 4.85.
The good news is that this business is very close. Just 10 more 5-star reviews takes it to 14,841 points from 3,060 reviews, which is exactly 4.85, and its rating moves up to 4.9.
How Google rounds your rating
Google shows your rating to one decimal place, rounded to the nearest tenth. In practice, that means:
- An exact average of 4.85 to 4.949 shows as 4.9.
- An exact average of 4.95 or more shows as 5.0.
- An exact average of 4.75 to 4.849 shows as 4.8.
That's why a perfect 5.0 is so hard to keep. With a single 1-star review, you'd need 79 five-star reviews to bring your average back up to 4.95.
Google star rating calculator
Enter how many reviews you have at each star level. The calculator shows your exact average, the rating Google displays, and how many reviews it takes to move up or down by 0.1.
Google star rating calculator
Enter how many reviews you have at each star rating.
Exact average: - from 0 reviews
Where to find your numbers: Google shows a bar for each star level on your profile, but not the exact count. Count your reviews at each level, then check that your total matches the review count Google shows.
How long it takes for your rating to update
Your rating doesn't change the moment a new review appears. Google says that after someone leaves a new review, "it may take up to 2 weeks to get an updated review score."
So be patient. If your rating hasn't moved, wait two weeks before you assume something's wrong. If any new reviews arrive during that time, especially low-star ones, recalculate with the new numbers before you raise a support ticket. A single 1-star review can cancel out the 5-star reviews you were waiting on.
Why your rating might not match your maths
- Delays: new reviews can take up to two weeks to count towards your score.
- Removed reviews: reviews Google removes or filters for breaking its policies no longer count. If your total review count has dropped, see why your Google reviews disappeared.
- Rounding: your exact average may sit just below a cut-off, like 4.8495 in the example above.
How to move your rating up faster
The only way to lift your average is more good reviews. The bigger your review count, the more new reviews it takes to move it, so a steady flow matters more than a one-off push.
- Ask every happy customer: most people are happy to leave a review if you ask at the right time. See how to get more Google reviews, including what Google doesn't allow.
- Reply to every review: it shows future customers you care, especially when a review is negative. See how to respond to negative Google reviews.
- Report fake reviews: if a review breaks Google's policies, you can ask Google to remove it. See how to report a Google review.
With RepU Pro, you can send review requests by email in seconds, and RepU follows up automatically after 24 hours. Insights shows your review average and trends from day one, so you can see how each new review moves your star rating.
Frequently asked questions
How does Google calculate my star rating?
Google says your review score is the average of all ratings published on Google for your business. Add up the stars from every review, divide by your number of reviews, and round to one decimal place.
Does Google round my rating up?
Google rounds to the nearest tenth. An exact average of 4.85 shows as 4.9, but 4.849 shows as 4.8.
Do star-only ratings count?
Yes. Every rating counts towards your average, whether or not the customer wrote a review.
How many 5-star reviews do I need to reach 5.0?
You need an exact average of 4.95 or more. With one 1-star review, that takes 79 five-star reviews. Use the calculator above to work it out for your own numbers.
Why hasn't my rating changed after new reviews?
Google says it may take up to two weeks for your review score to update. If new reviews arrived in the meantime, recalculate before you contact Google support.
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