Instant Calculation
Get your answer in seconds. Enter three numbers and the calculator does all the maths for you, no spreadsheets needed.
Google Review Calculator
Find out exactly how many 5-star reviews you need to hit your target Google rating, instantly.
Guide
How to Use the Calculator
1
Enter Your Current Rating
Type your current average rating like 4.2 or 3.8.
2
Add Your Review Count
Type how many reviews you currently have on Google.
3
Set Your Target and Calculate
Set your target rating and see how many five-star reviews you need.
Plan the Five-Star Climb
Going from a 4.2 to a 4.7 Google rating sounds simple but takes specific math. The calculator tells you exactly how many five-star reviews you need to collect to hit your target, given your current count.
Local businesses use it for review-campaign planning, agencies for client reporting, and SaaS teams for App Store ranking targets.
Benefits
Why Use This Calculator
Before & After View
See your current rating and projected rating side by side so you can visualise the improvement a batch of new reviews will make.
Live Star Preview
As you type a rating, the star display updates live so you always know exactly what the rating looks like in Google Search.
100% Private
All calculations happen in your browser. No data is sent to a server, so your business information stays completely private.
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FAQ
Frequently Asked Questions
Common questions about Google star ratings and review strategy.
How does Google calculate the star rating?
Google averages all your review scores. For example, if you have 100 reviews totalling 420 points, your rating is 4.2. Each new 5-star review adds 5 points to the total and raises the average by a small amount. The more existing reviews you have, the more new 5-star reviews are needed to move the needle.
Why does the calculator only add 5-star reviews?
The formula is designed to show the minimum effort required. Only 5-star reviews can raise your average above its current value. Reviews of 4 stars or less would either keep the average the same or lower it, so 5-star reviews are the only lever you can pull to reach a higher target.
Why can't I target a 5.0 rating?
Once you have any review below 5 stars, a perfect 5.0 average is mathematically impossible, no matter how many 5-star reviews you add, you can only approach 5.0 asymptotically. Google also rounds displayed ratings to one decimal place, so a 4.9 is effectively "perfect" in practice.
How do I get more Google reviews legitimately?
Google allows businesses to ask customers for honest reviews. You can send a review link by email or SMS after a purchase, add a QR code at your premises, or include a link in your email signature. Never offer incentives or pay for reviews, this violates Google policy and can result in penalties or removal of your listing.