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Google review calculator
How many 5-star reviews do you need to move from 4.2 to 4.5? With 50 reviews, the answer is 30. Enter your rating, review count and goal, and this calculator shows how many 5-star reviews it takes and how many weeks that is at your pace. It runs in your browser and saves nothing.
How many 5-star reviews do you need?
These checks apply OpenGMB's own reading of Google's published policies. They are not legal advice, and they are not made, approved or endorsed by Google. Google decides what it accepts and changes its policies, so a pass here does not guarantee Google will publish your text.
What do you get from the Google review calculator?
The number of 5-star reviews
The exact count to reach your target if every new review is 5 stars, rounded up.
Weeks at your pace
Add how many reviews you get a week and see how long the climb takes.
What one 1-star review costs
How many 5-star reviews it takes to win back the rating after a single 1-star review.
How many 5-star reviews do I need to raise my Google rating?
It depends on your rating, how many reviews you have and your target. Three worked examples from the calculator:
| Rating now | Reviews | Target | 5-star reviews needed | Weeks at a pace |
|---|---|---|---|---|
| 4.2 | 50 | 4.5 | 30 | 6 at 5 a week |
| 3.8 | 100 | 4.3 | 72 | 15 at 5 a week |
| 4.5 | 200 | 4.7 | 134 | 14 at 10 a week |
How does the Google review calculator work?
The formula is: reviews needed = review count x (target minus current) divided by (5 minus target), rounded up. It assumes every new review is 5 stars.
It is simple math, so the answer is exact for the average. Google shows one decimal place and does not publish how it rounds, so aim a few hundredths above your target to see it on your profile.
How long will it take to reach my target rating?
Divide the reviews you need by the reviews you get a week. The calculator does this when you fill in the last box. A steady ask beats a burst: a few reviews every week is easier to keep up than a big push once a quarter.
How many reviews does a business need to rank?
There is no fixed number. Reviews are one signal among several, and a competitor with more reviews can still rank below you. Use this calculator to set a rating goal, not a ranking promise.
How do I get those reviews without breaking Google's rules?
Ask every customer the same way. Google does not allow paying for reviews, asking only happy customers, or discouraging negative reviews (policy checked 2026-10-24).
The review link page gives you your link and a QR code, and the templates page gives you messages to send.
Questions about the Google review calculator
What is the formula?
Reviews needed = count x (target minus current) divided by (5 minus target), rounded up. It assumes every new review is 5 stars.
Why is my rating not the number I expected?
Google rounds what it shows, and its exact rounding is not published. Aim slightly above your goal.
Do old reviews drop off?
Reviews stay until they are removed. Google can remove reviews that break its policies, which changes your average.
Can I reach a 5.0 rating?
Not by adding reviews, unless every review you have is already 5 stars. The calculator asks for a target below 5.0.
Does the calculator save what I type?
No. It runs in your browser. Nothing is sent to a server or stored.
Ask for the reviews without chasing anyone
The calculator tells you how many. OpenGMB review requests send your Google review link by email, with an optional reminder, and show you which requests were opened and clicked.