Google review calculator

The short answer: multiply your review count by the gap between your target and your current average, then divide by the gap between 5 and your target. Round up.

5-star reviews needed = reviews × (target − current) ÷ (5 − target)

With 50 reviews averaging 4.2, reaching 4.5 takes 50 × 0.3 ÷ 0.5 = 30 reviews. Reaching 4.8 takes 150, and 4.9 takes 350. The divisor is why: each new 5-star review can only pull your average toward 5 by the distance that's left, so the last tenth below 5 costs the most.

The count doubles when your review count doubles, so a business with 200 reviews has to work four times as hard as one with 50 to move the same distance. That cuts both ways: one bad review barely dents a big profile.

Google says your review score is "the average of all ratings published on Google" for your business (from its help page on review scores). On your profile it shows that average with one decimal. So a 4.3 is a rounded number: the real average behind it could be anywhere from 4.25 to 4.34.

Google doesn't document how it rounds, so our calculation assumes a simple average rounded the normal way (4.25 shows as 4.3). When the rounding hides your exact total, the calculator gives a range and tells you to plan for the bigger number. That number works whichever way Google rounds. If you know your exact average, type it with two decimals, like 4.27, for one exact answer.

Why your rating may not match the calculator yet

• New reviews take time to count. Google says it can take up to 2 weeks for your score to update after a new review.
• Removed reviews stop counting. The score averages ratings that are published, so a review Google takes down for breaking its rules shouldn't count once the score updates. Our guide on removing Google reviews explains which ones Google takes down.
• Reviews from other sites are separate. Google says a profile can also show reviews from other review sites. The score averages ratings published on Google, so leave those out of the calculation.

Only while every review is 5 stars. A true 5.0 average means every rating is a 5, so a single 4-star review rules it out for as long as it stands. What you can get is a shown 5.0: if Google rounds normally, an average of 4.95 or more shows as 5.0. Put 5.0 in the calculator and it tells you how far away that is.

For most businesses it isn't worth chasing. In BrightLocal's 2026 survey of 1,002 US adults, 68% said they would only use a business with 4 stars or more and 31% wanted 4.5 or more, but only 10% said they'd only use a business with a five-star rating (BrightLocal, 2026). Our advice: once you're above 4.5, put the effort into getting new reviews every month rather than a perfect score.

It depends almost entirely on how many reviews you already have. Here is one 1-star review landing on a 4.8 average:

"Google shows" assumes normal rounding. With 10 reviews, one 1-star review costs you three tenths. With 100, the number Google shows doesn't move.

What to do about it: reply to the review calmly within a day or two (our guide to responding to Google reviews has the steps), report it only if it breaks Google's rules, and keep asking every customer for a review. Don't try to drown it with fake or bought reviews: Google's content policy bans paid reviews and content that isn't based on a real experience, and our guide to fake Google reviews covers what happens to them.

• From 4.3 to 4.5

  Maple Street Bakery (a made-up example) shows 4.3 from 64 reviews and wants 4.5. Its true average could be anything from 4.25 to 4.34, so it needs 20 to 32 more 5-star reviews in a row. If Google rounds normally, 4.5 could show after 13 to 24.

• From 4.7 to 5.0

  Harbor Dental (made up) shows 4.7 from 120 reviews. A true 5.0 is impossible, because at least some of those reviews are under 5 stars. A rounded 5.0 needs an average of 4.95: that's 500 to 720 more 5-star reviews in a row, at least four times as many reviews as it has today.

• Two 1-star reviews in a week

  Juniper Hair Studio (made up) shows 4.6 from 35 reviews, then gets two 1-star reviews. Its average drops to 4.37 to 4.43, which shows as 4.4. Getting back to 4.6 takes 10 to 15 5-star reviews in a row.

The calculator tells you how many. Getting them comes down to asking every customer, at the right moment, with a link that opens the review form directly.

• Ask everyone, not only the happy ones. Google's content policy says businesses must not "selectively solicit positive reviews from customers", so the same request goes to every customer.
• Make it one tap. Our free review link and QR code generator gives you a link that opens Google's review form for your business.
• Never pay or offer anything for a review. Google's policy bans incentives such as discounts or free goods in exchange for a review.
• Keep the pace steady. Google's guide to local ranking says more reviews and positive ratings can help your local ranking, and a flow of new reviews every month is easier to keep up than a one-off push.

Our guide on how to get more Google reviews has the scripts and message templates. Every new review also deserves a reply: Mekomi drafts one for each review, and can send 4 and 5 star replies automatically once you switch that on.