Calculate a weighted average where observations carry different importance.
Each value contributes in proportion to its weight, so the weighted mean shifts toward heavily weighted observations. When all weights are equal it reduces to the arithmetic mean. Using an unweighted mean where observations represent different sample sizes is one of the most common analytical errors, and it systematically misrepresents the aggregate.
Weighted Mean
Weighted mean = Σ(value × weight) ÷ Σweight
Weighted mean = Σ(value × weight) ÷ Σweight Each value contributes in proportion to its weight, so the weighted mean shifts toward heavily weighted observations. When all weights are equal it reduces to the arithmetic mean.
Using an unweighted mean where observations represent different sample sizes is one of the most common analytical errors, and it systematically misrepresents the aggregate.
This calculator takes 6 inputs: Value 1, Weight 1, Value 2, Weight 2, Value 3, Weight 3. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.