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Rating models

Weighted average calculator

Calculate a star rating with a different weight per review in each group.

Model estimate, not a platform prediction. Results may differ from real service ratings. Platforms can use unpublished weights, moderation, eligibility rules and rounding. This calculator applies only the formula below.

Your inputs

Reset example
Weighted average · model result
4.017 / 5

100 reviews in the included groups. Group averages can make the result approximate.

Results are rounded to three decimal places.

How it works

Σ(rating × count × weight) ÷ Σ(count × weight)

Weights are your assumptions. A weight of 2 makes each review count twice as much as a review with weight 1. This is not Amazon’s proprietary algorithm.

Results update as you type. Calculations run in your browser; submitting with JavaScript disabled sends the numbers to the server to calculate the result.

Reach a target

Minimum additional 5-star reviews. Both panels use the assumptions above. Existing reviews are not edited or removed except by this method’s time window or trimming rule.

116

additional reviews needed

Simulate new ratings

4.092 / 5

110 reviews in the included groups. Group averages can make the result approximate.

Other rating methods