How Google Business Ratings Are Calculated

Google says a Business Profile's review score is the average of all ratings published on Google for that business, on a scale of 1 to 5 stars. That sounds simple, and it is, but the maths has some consequences that surprise owners, particularly for businesses with fewer reviews.

Written by Konrad Weber · Reviewed by Andrew Foster, Review Removal Specialist · Updated 2026-10-11

What Google says, and what it does not

Google's Business Profile help page on review scores states that the score is the average of all ratings published on Google for the place, on a 1 to 5 scale with 5 the highest. It also says that after someone leaves a new review, it may take up to 2 weeks for the score to update. Search and Maps can show the score alongside the total number of reviews and selected top reviews.

Google does not publish a more detailed formula. You will see claims online that Google weights recent reviews more heavily, or reviews from Local Guides, or that it uses a "Bayesian" average. Google's help pages do not say this, so we do not repeat it as fact. Treat any precise formula from a third party with caution.

What counts towards the score

Published Google ratings, including rating-only reviews with no text.
Not reviews that Google has removed or not published.
Not reviews from other websites. Some profiles show reviews from other sites, and Google says those are gathered automatically from the web; for concerns about them, you need to contact the originating site.
Not photo updates. Google says photo updates do not affect the review score.

How an average works: worked examples

An average is the total of all star ratings divided by the number of ratings. The examples below are hypothetical and show the arithmetic only. They do not describe any particular business.

Example 1: One one-star review on a small profile

For example, imagine a business with 8 reviews: six 5-star and two 4-star.

Total stars: (6 × 5) + (2 × 4) = 30 + 8 = 38.
Average: 38 ÷ 8 = 4.75.
A one-star review arrives. Total: 39. Count: 9. Average: 39 ÷ 9 = 4.33.
If that one-star review is later removed, the score returns to 38 ÷ 8 = 4.75.

On a small profile, one review moves the average by almost half a star.

Example 2: The same review on a medium profile

Now imagine a business with 20 reviews averaging 4.6, which means 92 stars in total.

A one-star review arrives. Total: 93. Count: 21. Average: 93 ÷ 21 = 4.43.
To get back to 4.6 with new five-star reviews alone, you need (93 + 5n) ÷ (21 + n) to reach 4.6. Solving gives n = 9: (93 + 45) ÷ 30 = 138 ÷ 30 = 4.6.
In other words, it takes nine new five-star reviews to offset one one-star review here. Removing the one-star review, if it breaches policy, restores 4.6 directly.

Example 3: A wave of reviews on a larger profile

Imagine a business with 400 reviews averaging 4.5, or 1,800 stars in total, that receives ten one-star reviews in a weekend.

Total: 1,810. Count: 410. Average: 1,810 ÷ 410 = 4.41.
The drop is smaller than on a small profile, but noticeable, and it is the kind of pattern review bombing creates.

How the score is displayed

Google typically shows the score to one decimal place, with stars beside it. Google does not publish its exact rounding rule, so a 4.43 might display as 4.4. Small changes can therefore move the displayed figure across a threshold, or not move it at all.

What this means in practice

Small businesses are most exposed. With fewer than about 20 reviews, a single unfair rating has an outsized effect.
A steady flow of genuine reviews is the best protection. Asking every customer, not only the happy ones, is allowed and builds resilience. Selectively asking only satisfied customers, or offering incentives, is not.
Removal and dilution are different. Removing a review that breaks the rules restores the average directly. Genuine negative reviews can only be diluted by more genuine reviews.
Expect a lag. After a removal or a new review, the score may take up to 2 weeks to update.

When a single review is worth challenging

If a review on your profile is fake, written by a competitor or a former employee, or otherwise breaches Google's policies, removing it may make a meaningful difference to your average, as the examples show. If it is a genuine but unhappy customer, the better investment is a good reply and more reviews. Our guide on removing a one-star review explains which one-star reviews can realistically be challenged.

G-DEFENCE assesses and challenges policy-violating and unlawful reviews for Australian businesses through Google's official channels, with no upfront fee. Our cost guide sets out what removal costs. If you would like to know whether a review dragging down your score has a real basis for a complaint, request a free assessment.

Sources

Frequently asked questions

Do older reviews count less than recent ones?

Google's help page describes the score as the average of all published ratings and does not mention any time weighting. Readers may still pay more attention to recent reviews when deciding.

Why is my review count different from the number of reviews I can see?

Counts and visible reviews can differ temporarily while Google processes new or removed reviews, and Google notes that score updates can take up to 2 weeks.

Does replying to reviews improve my rating?

Replies do not change the average directly. They can influence how readers perceive your business, and a reviewer may update their review after a good response.

Do edited reviews change the score?

If a reviewer changes their star rating, the new rating replaces the old one in the average. Google notes the review date updates to show the latest change.

Can I see my score to two decimal places?

Google typically shows one decimal place. You can calculate a more precise figure yourself from the star breakdown if your profile shows how many reviews sit at each star level.