Free · Averages and ratings

Five-Star Rating from Vote Counts

Calculate a one-to-five-star arithmetic average from the number of ratings at each level.

Calculator inputs

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Enter the known values in the units shown. Results update as you type.
Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
Use the worked example to check the method. Reset restores the starting fields.

Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.

Eight five-star ratings and two four-star ratings produce 48 star points across 10 ratings, for an average of 4.8 stars.

Average stars = (5n₅ + 4n₄ + 3n₃ + 2n₂ + n₁) ÷ (n₅ + n₄ + n₃ + n₂ + n₁)

Enter these known values and leave the other values blank.

Counts are nonnegative whole numbers and at least one rating is required. Enter zero explicitly for unused star levels.
Each rating contributes equally. This model does not reproduce a platform’s moderation, recency weighting, Bayesian adjustment or rounding policy.
Average rating and total count are outputs. An average alone cannot identify the five underlying rating counts.

Not for valid positive-count inputs in this one-to-five-star model.

Only if the platform uses the same unweighted arithmetic mean and comparable rounding.

Ratings represent nonnegative whole-number counts; at least one vote is required for an average.