Free Google Review Calculator
Find out exactly how many 5-star reviews you need — free, no signup, instant results.
How many 5-star reviews do I need?
Enter your current rating, review count and target to see exactly how many new 5-star reviews it takes.
Recover from a 1-star review
See how far one 1-star review drags your average down — and how many 5-star reviews undo the damage.
Time to target
How long until you hit your target at your current review pace? Enter your monthly review rate.
Beat a competitor
How many new 5-star reviews do you need for your average to overtake a competitor’s?
Use this free Google review calculator to find out exactly how many 5-star reviews your business needs to reach your target rating and improve Google rating — no signup. This Google rating calculator also includes three extra modes — 1-star recovery, time-to-target and competitor comparison — so you can plan your review strategy with real numbers instead of guesswork.
Wondering how many reviews to reach 4.5 stars, or how many 5-star reviews you need for 4.8? Enter your current average and review count above — the calculator gives you the exact number in one click.
How the maths works
Your Google rating is a simple average: Google adds up the star values of all your reviews and divides by the number of reviews. So a business with 85 reviews averaging 4.2 stars has 4.2 × 85 = 357 total “star points”.
To work out how many new 5-star reviews (N) you need for a target rating, solve: (current total + 5 × N) ÷ (current reviews + N) = target. Rearranged, that gives N = (target × reviews − total) ÷ (5 − target), rounded up — because you can’t earn a fraction of a review. The same idea powers all four calculator modes above.
Worked example: a business at 4.2 stars with 85 reviews wants to reach 4.6. Total star points: 4.2 × 85 = 357. Then N = (4.6 × 85 − 357) ÷ (5 − 4.6) = 34 ÷ 0.4 = 85. So it needs 85 new 5-star reviews to reach 4.6 stars.
How Many 5-Star Reviews Do You Need? (Quick Answer Table)
| Current standing | To reach 4.5 ★ | To reach 4.6 ★ | To reach 4.8 ★ | To reach 4.9 ★ |
|---|---|---|---|---|
| 100 reviews at 4.0 stars | 100 reviews | 150 reviews | 400 reviews | 900 reviews |
| 200 reviews at 4.3 stars | 80 reviews | 150 reviews | 500 reviews | 1,200 reviews |
Your numbers will differ — enter your own rating above to get your exact target.
Got your target? Now get the reviews
Got your target? Now get the reviews — use our free Google Review Link & QR Code Generator to create a shareable review link and a printable QR code that makes it effortless for happy customers to leave you 5-star reviews.
Frequently asked questions
How many 5-star reviews do I need to reach 4.5?
It depends on your current rating and how many reviews you already have — the more reviews you have, the more new 5-star reviews it takes to move the average. As a guide, a business at 4.2 stars with 85 reviews needs 51 new 5-star reviews to reach 4.5. Enter your own numbers in the calculator above for an exact answer.
Can a business reach a perfect 5.0 rating?
Only if every single review is 5 stars. Once even one lower review exists, new 5-star reviews can push the average closer and closer to 5.0, but the maths never quite gets there — and Google rounds the rating it displays. In practice, 4.8–4.9 is the realistic ceiling, and customers already read that as excellent.
How much does one 1-star review hurt?
It depends on your review count: the fewer reviews you have, the bigger the dent. For example, a business at 4.2 stars with 85 reviews drops to about 4.16 after a single 1-star review — and needs 4 new 5-star reviews to climb back to 4.2. Try the 1-star recovery mode above with your own numbers.
How long does it take to improve a Google rating?
It comes down to review velocity — how many new reviews you earn each month. If you need 85 new 5-star reviews and you earn 10 a month, you’re looking at about 9 months of steady effort. Use the time-to-target mode above: enter your monthly review rate and it estimates the month you’ll hit your goal.
Do old reviews count less?
No. Google calculates your star rating as the simple average of all your reviews, so an old 5-star review counts exactly the same as a new one. That is also why a steady stream of fresh 5-star reviews is the only reliable way to lift your average.
Related Free Tools
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