App rating lift calculator
Find out exactly how many 5-star reviews you need to reach your target rating — and how many in-app prompts to send to get there.
Enter your current rating, total review count, and target rating. Add your review prompt response rate to see how many prompts you need to send to collect enough reviews.
App rating lift calculator inputs and results
How the calculation works
The current sum of star values is current rating × current review count. Each new 5-star review adds 5 to the sum and 1 to the count. The new average is (current sum + 5n) ÷ (current count + n). Setting this equal to the target and solving gives n = current count × (target − current rating) ÷ (5 − target rating).
This assumes all new reviews are 5-star — the most optimistic scenario. In practice, a prompt campaign will yield a mix of ratings. Users who had a bad experience often leave reviews unprompted; a prompt campaign primarily mobilises satisfied users who wouldn't have reviewed otherwise. The real number of reviews needed will be higher than this estimate by whatever fraction of prompt responses are below 5 stars.
Prompts needed = reviews needed ÷ prompt response rate. A 20% response rate means 1 in 5 users who receive a prompt leave a rating — so collecting 425 new reviews at 20% requires approximately 2,125 prompt impressions. Time prompts immediately after a positive user action for the highest response rate.
About this tool
This tool calculates the number of new 5-star reviews needed to lift an app's average rating to a target score. Inputs: current average rating, current review count, target rating, and optionally a review prompt response rate to calculate the number of in-app prompts needed. The formula is exact — it solves for the number of additional 5-star reviews that shift the weighted average to the target. Handles edge cases including already-achieved targets and impractically high targets.
Frequently asked questions
How is the number of reviews calculated?
The average rating is (sum of all star values) ÷ (total review count). The current sum of star values is current rating × current count. To reach a target rating with additional 5-star reviews, we need to solve for n such that (current sum + 5n) ÷ (current count + n) = target rating. Rearranging gives n = current count × (target − current rating) ÷ (5 − target rating). All additional reviews are assumed to be 5-star — in practice you'll get a mix, so this is the optimistic lower bound.
Why do I need so many reviews to move my rating up?
The average is weighted by all existing reviews. With 1,000 reviews at 3.5 stars, you have a cumulative star score of 3,500. Adding one 5-star review moves the average to 3,501/1,001 = 3.498 — barely noticeable. To move significantly you need a volume of new ratings that's meaningful relative to your existing base. This is why older apps with large review counts are hard to move — they have significant inertia — and why recovering a bad average is much harder than maintaining a good one.
When does Apple and Google reset the rating?
App Store: ratings can be reset for a major update — you can request this in App Store Connect. After a reset, the "Current Version" rating starts fresh while the "All Versions" rating is preserved. Google Play shows a rolling average weighted toward recent reviews, so older ratings naturally lose influence over time without requiring a manual reset. Resetting is worth considering if your rating reflects an older, significantly worse version of the app, but you'll lose the social proof of a high review count.
How do I get more reviews without violating App Store guidelines?
Use the native in-app review prompt API — SKStoreReviewRequest on iOS, In-App Review API on Android. Apple allows showing this prompt a maximum of three times per year per user. Google has fewer explicit limits. The key is timing: prompt immediately after a positive user action (completing a level, a successful workflow, a positive outcome), not randomly. Conversion rates for well-timed prompts typically range from 10–40% — this calculator lets you model how many prompts you need at your actual response rate.