How to use the reviews needed to raise rating calculator
Working out how many reviews it takes to lift an average comes down to one formula: reviews needed = current review count × (target rating − current average) ÷ (maximum − target rating). A listing that already carries a lot of reviews has a much larger numerator, so the count climbs quickly, and setting the target close to the maximum drives the denominator towards zero, which makes the requirement explode.
Two cases are mathematically impossible. If the target equals the maximum the denominator is zero and no number of new reviews ever gets there, and if the target is at or below the current average there is nothing to raise. Rather than quietly hiding the result, the calculator explains which of those two applies.
The count is rounded up. Rounding down would leave you fractionally short of the target even after collecting every review shown. As a check, the calculator also shows the average you would end up with, computed from the review count displayed on screen, so you can confirm it really lands at or above the target. Since new reviews are never all perfect, enter an expected rating to see the realistic count as well.
Frequently asked questions
The average includes every existing review. Lifting a 1,000-review average by 0.1 takes roughly ten times as many new reviews as lifting a 100-review average by the same amount.
Use the average of the reviews you have actually received over the last few months. If that value sits at or below your target, new reviews will never get you there, and the calculator says so.