Free tool
Google Review Calculator
How many 5-star reviews does it take to get from 4.2 to 4.5? Enter your current rating, your number of reviews and the rating you’re aiming for, and you get the number right away. Free, no sign-up, nothing is sent anywhere.
Fill in all three boxes and the answer shows up right here.
How the math works
Google’s review score is the average of all ratings published for your business. If you have N reviews averaging R and you add 5-star reviews, the number you need is:
5-star reviews needed = (target − current rating) × number of reviews ÷ (5 − target), rounded up
Example: 50 reviews at 4.2, aiming for 4.5. (4.5 − 4.2) × 50 ÷ (5 − 4.5) = 15 ÷ 0.5 = 30 five-star reviews. Check: (4.2 × 50 + 5 × 30) ÷ 80 = 360 ÷ 80 = 4.5.
The more reviews you already have, the less each new one moves the needle. And the closer your target is to 5, the more you need: at 4.8, each 5-star review only closes a 0.2-point gap. That’s why a perfect 5.0 is gone for good once a lower review is on the board.
What the number doesn’t tell you
The calculator assumes every new review is 5 stars. In real life you don’t pick the stars, and that’s fine: Google’s own tips for getting reviews point out that a mix of positive and negative feedback often feels more trustworthy than a wall of perfect scores.
What moves a rating is volume from customers who liked the work, which means asking every customer, the same way. Asking only the happy ones is out: Google’s policy bans selectively soliciting positive reviews and offering discounts or freebies for reviews. The full list is on our Google review rules page.
How to use the calculator
Look up your rating and review count
On your Google Business Profile, in Maps or Search: the score out of 5 and the number of reviews sit side by side.
Pick a realistic target
One tenth of a point, then the next. Going from 4.1 to 4.3 takes a few months if you ask after every job.
Turn the number into a habit
Divide the number by your jobs per month and you know how many requests to send. Copy-paste texts are in the review request templates.
Frequently asked questions
How does Google calculate my rating?
It’s the average of all ratings published for your business, on a 1-to-5-star scale (Google’s help).
Why didn’t my rating change after a new review?
Google says it may take up to 2 weeks for the score to update after someone leaves a review (Google’s help). If the review itself is missing, see Google reviews not showing.
Is the result exact?
The math is exact for the numbers you enter. If the rating you type isn’t your exact average (4.3 instead of 4.27, say), the answer can be off by a review or two.
Can I delete a bad review to bring my rating up?
No. Only reviews that break Google’s policies can be taken down. Here’s how that works: remove a Google review.
Is the calculator free?
Yes, no sign-up. The math runs in your browser; nothing is sent or stored.