beyondreviews.
Statistics

Wilson Score Calculator

Enter your 1-to-5 star counts and get the Wilson lower bound — the statistically honest floor of your true rating. See how many reviews you need to reach a target rating.

Result
WILSON LOWER BOUND
4.49 / 5
95% confidence lower bound
WEIGHTED AVERAGE
4.67
TOTAL REVIEWS
212
TO REACH 4.5
5 more 5-star reviews
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Common questions
What is the Wilson score and why does it matter for product ratings?
The Wilson score is the lower bound of the 95% confidence interval for your true rating. A product with 4.9 stars from four reviews and one with 4.7 stars from 400 reviews are not equally trustworthy. The Wilson score accounts for sample size, so a well-reviewed product ranks above one with suspiciously few reviews even if the average looks higher.
How is the Wilson score calculated for star ratings?
Star ratings are normalised to a 0-to-1 scale before applying the standard Wilson interval formula. A 5-star rating maps to 1.0 and a 1-star rating maps to 0.0. The formula then produces a lower confidence bound at the 95% level, which is scaled back to a 1-to-5 range for readability.
How many reviews do I need to reach my target rating?
The calculator estimates how many additional 5-star reviews are needed to bring your Wilson lower bound to a target value, assuming future reviews match a mix weighted toward positive. This is an estimate — actual results depend on the rating distribution of reviews you actually receive.
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