Guide
How many 5-star reviews does it take to raise your Amazon rating?
Part 1
From 4.0 stars, reaching 4.5 takes as many 5-star reviews as you already have
Do this first
- Open your listing and note the star rating and the number of ratings under the title.
- Find your rating's row and the column nearest your count.
- For your exact numbers or a target other than 4.5, run the Star Rating Calculator.
| Rating now | 50 reviews | 100 reviews | 250 reviews | 500 reviews | 1,000 reviews |
|---|---|---|---|---|---|
| 3.5 | 100 | 200 | 500 | 1,000 | 2,000 |
| 3.6 | 90 | 180 | 450 | 900 | 1,800 |
| 3.7 | 80 | 160 | 400 | 800 | 1,600 |
| 3.8 | 70 | 140 | 350 | 700 | 1,400 |
| 3.9 | 60 | 120 | 300 | 600 | 1,200 |
| 4.0 | 50 | 100 | 250 | 500 | 1,000 |
| 4.1 | 40 | 80 | 200 | 400 | 800 |
| 4.2 | 30 | 60 | 150 | 300 | 600 |
| 4.3 | 20 | 40 | 100 | 200 | 400 |
| 4.4 | 10 | 20 | 50 | 100 | 200 |
- Every cell solves one equation: (rating now times reviews, plus 5 times N) divided by (reviews plus N) equals 4.5. The Star Rating Calculator solves the same one for any target.
- The rule of thumb is 2 times the gap times your count. At 4.2 stars and 250 reviews, the gap to 4.5 is 0.3, so 2 times 0.3 times 250 is 150.
- The count scales with your history. A listing at 3.8 stars needs 70 new 5-star reviews at 50 reviews and 1,400 at 1,000, which is why an older listing moves slowest.
Part 2
Each tenth of a star costs more than the one below it
Do this first
- Set your next target one tenth above today's rating.
- Read the reviews that tenth takes at your count below.
- Check the listing again once that many new reviews have arrived.
| Step | At 100 reviews | At 500 reviews |
|---|---|---|
| 3.5 to 3.6 | 8 | 36 |
| 3.6 to 3.7 | 8 | 39 |
| 3.7 to 3.8 | 9 | 42 |
| 3.8 to 3.9 | 10 | 46 |
| 3.9 to 4.0 | 10 | 50 |
| 4.0 to 4.1 | 12 | 56 |
| 4.1 to 4.2 | 13 | 63 |
| 4.2 to 4.3 | 15 | 72 |
| 4.3 to 4.4 | 17 | 84 |
| 4.4 to 4.5 | 20 | 100 |
- 4.4 to 4.5 takes 20 at 100 reviews, and 3.5 to 3.6 takes 8. Each new 5-star review pulls the average up by its distance from 5, and that distance shrinks as the rating climbs.
- At 500 reviews the same steps take 100 and 36. Each row assumes the count in its column, so the rows don't add up to Part 1: after each step a listing holds more reviews, and the next tenth costs more again.
- 5.0 can't be reached once a listing holds one review under 5 stars, because the average only approaches it.
Part 3
Real new reviews average under 5 stars, so plan for more than the table
Do this first
- Average the stars of your last 20 reviews to see what new ones bring.
- If that average is 4.5 or below, fix what the low reviews name before chasing count.
- Multiply the table's count by the factor below for your average.
| New reviews average | New reviews needed | Times the 5-star count |
|---|---|---|
| 5.0 | 150 | 1.0x |
| 4.8 | 250 | 1.7x |
| 4.7 | 375 | 2.5x |
- At an average of 4.7, it takes 2.5 times as many. The gap a new review closes is its stars minus 4.5, so 0.2 at 4.7 against 0.5 at 5. In the example, 150 becomes 375.
- At an average of 4.5 or below, the rating never reaches 4.5. New reviews averaging 4.4 only pull the rating toward 4.4, so it stalls below 4.5 whatever the count.
- Amazon says "we don't use a simple average." Its system weighs how recent a review is and whether the reviewer bought the item on Amazon,1 so the displayed rating can move faster or slower than this arithmetic. Treat each count as an estimate and check the listing as reviews arrive.
- Run your own numbers in the Star Rating Calculator, which also shows the conversion lift on the way. A blog can add it with the embed code.
See what your reviews say, beside your sales
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Sources
- Amazon.com. "How are ratings calculated?", customer reviews section of a product detail page. Read October 24, 2026. Link