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Google review rating calculator: how many five-star reviews to reach your target
This calculator takes the number of five-, four-, three-, two- and one-star reviews on your profile and a target average, and works out your current average (to two decimals and to the one decimal review sites usually show), how many new five-star reviews it would take to reach the target with nothing else changing, and what one more five-star or one-star review would do. It is arithmetic on your own counts, not a forecast, and the numbers you type are not stored or sent anywhere.
Run your own numbers
The fields hold example numbers, made up to show the arithmetic. Replace them with the counts from your own profile: open your reviews, sort or filter by rating, and count each star level.
Results
- Reviews counted
- 44
- Your average, to two decimals
- 4.39
- The same average to one decimal, as review sites usually show it
- 4.4
- Five-star reviews needed to reach the target average
- 10
- Your average after those reviews
- 4.50
- Your average if the next review is five stars
- 4.40
- Your average if the next review is one star
- 4.31
Without JavaScript the fields do not recompute: the results shown are the worked example.
How the numbers are worked out
- Reviews counted = the five star counts added up.
- Total stars = 5 × five-star reviews + 4 × four-star + 3 × three-star + 2 × two-star + 1 × one-star.
- Average = total stars ÷ reviews counted. Google's help says its review score is the average of all ratings published on Google for the business; the calculator uses that plain average.
- Five-star reviews needed = the smallest whole number of new five-star reviews that lifts the average to the target, with nothing else changing: (target × reviews counted − total stars) ÷ (5 − target), rounded up. If your average is already at or above the target, none are needed. An average of exactly 5 is reachable only when every review is five stars.
- The last two lines show what one more review does: the next five-star review and the next one-star review, each on its own.
The worked example
Made-up numbers, chosen to keep the arithmetic easy to follow. They are not anyone's real figures.
| Step | Example |
|---|---|
| Five / four / three / two / one-star reviews | 30 / 8 / 2 / 1 / 3 |
| Reviews counted | 44 |
| Total stars | 193 (150 + 32 + 6 + 2 + 3) |
| Average | 4.39 (193 ÷ 44), shown as 4.4 |
| Target average | 4.5 |
| Five-star reviews needed | 10 ((4.5 × 44 − 193) ÷ 0.5) |
| Average after those reviews | 4.50 (243 ÷ 54) |
| If the next review is five stars | 4.40 (198 ÷ 45) |
| If the next review is one star | 4.31 (194 ÷ 45) |
How to read the result
The number that matters is how many reviews it takes, not the decimals. On a profile with a few dozen reviews, one review moves the average by a tenth or more; on a profile with hundreds, the same review barely shows. That is why the figure that lifts a small profile is a steady stream of reviews from every customer, asked the right way, rather than any single review. The related answer on getting more reviews the right way covers how to ask, and what the rules forbid: no reward of any kind for a review, and no asking only the happy customers.
Two cautions. Google's help page does not say how it rounds the score it displays, and it says a new review can take up to two weeks to show in the score, so the one-decimal figure on your profile may lag or differ slightly from the plain average here. And the calculator assumes nothing else changes: a review that is edited, deleted or removed moves the average too. The related answer on how Google works out your star rating covers both, and the answer on how many Google reviews you need puts the count in context. This is arithmetic on your own numbers, not a forecast of what customers will post.
Sources
Related answers
- How does Google work out your star rating, and do old reviews ever expire?
- How many Google reviews does a business need?
- How do you get more reviews the right way?
- How should a business respond to a negative Google review?
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