Weighted mean calculator
Enter values and matching weights. See the result, weighted sum and total weight.
All calculations stay in your browser.
How do I use this page?
- Enter or import your data.
- Choose settings and select Calculate.
- Review the method and download the result.
Method, example and limitations
Weighted mean = Σ(w × x) / Σw. Weights can be counts or relative importance; they must be non-negative with a positive total. Zero contributes nothing. Percentages need not total 100: we normalise by the total weight.
Values 10; 20; 30 and weights 1; 2; 1: (10 + 40 + 30) / 4 = 20. A simple mean of group means is valid only for equally sized groups.