Raising a 3.9 rating back over four stars

Why 3.9 is a different world from 4.0

Ratings are not read as a continuum, they are read against two thresholds. 68 percent of consumers say they will only use a business with four or more stars, and 31 percent will only consider one at 4.5 or better. Both thresholds moved up sharply in a year, from 55 percent and 17 percent respectively.

So a move from 3.9 to 4.0 is worth a great deal more than a move from 4.2 to 4.3, and a move from 4.4 to 4.5 is worth more again. Between the thresholds, a tenth of a star buys almost nothing.

The arithmetic, worked twice

The mechanics are simple enough to do on paper. An average of 3.9 across 40 reviews means a point total of 156. To reach an average of 4.0 you need five star reviews until the total divided by the count clears 4.0, which happens after 4 of them: 176 points across 44 reviews. To reach 4.5 the same business needs 48: 396 points across 88 reviews.

The ratio is the point. 4 reviews against 48, a factor of twelve, for two targets that sound adjacent. Repeat it with a larger base and the shape holds: at 3.9 across 100 reviews, 390 points, you need 10 five star reviews for 4.0 and 120 for 4.5.

Now put the collection rate against it. If a business earns 3 new reviews a month, the 4.0 target is under two months of ordinary work and the 4.5 target is 16 months. And 74 percent of consumers want reviews from the last three months, so a campaign that takes sixteen months never presents as fresh.

Five star reviews needed from an average of 3.9

Existing reviews	To reach 4.0	To reach 4.5
20	2	24
40	4	48
60	6	72
100	10	120
200	20	240

Rounded up to whole reviews. The 4.5 column is twelve times the 4.0 column at every base, which is the whole argument for picking the nearer target.

Which target to actually pick

If you are below 4.0, that is the campaign. It is short, it is measurable, and it moves you past the threshold that 68 percent of consumers apply. Announce nothing, ask the customers you already served well, and stop when the average clears.

If you are between 4.0 and 4.4, treat 4.5 as a byproduct of steady collection rather than a project. The arithmetic says a push is expensive and the recency data says a slow steady stream is worth more anyway.

Questions and answers

Is 4.0 really a threshold?

For 68 percent of consumers, yes: they say they will only use a business with four or more stars. The share requiring 4.5 or better is 31 percent.

Can I get there faster by deleting bad reviews?

No, and attempting it is the expensive mistake. The arithmetic above only needs ordinary new reviews, which is why it is the cheaper route.

How long does it take?

At three new reviews a month, reaching 4.0 from 3.9 with 40 reviews takes under two months. Reaching 4.5 takes about sixteen.

Does the count matter as much as the average?

Less than people assume. The thresholds consumers describe are about the average, while the count decides how hard the average is to move.

Sources

BrightLocal, Local Consumer Review Survey 2026 The 4.0 and 4.5 thresholds, their year on year change and review recency
Google Search Central, Local business structured data How aggregate rating data is expressed for machines