Weighted Average Calculator

Calculate an average when observations have different importance.

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Formula / Calculation Method

Weighted mean = sum(value × weight) / sum(weight).

10 with weight 1 and 20 with weight 3 have a weighted average of 17.5.

Weights must be positive and need not be percentages.

Calculate an average when observations have different importance.

Add one row per observation, with its value and positive weight.

Select Calculate after entering your values. Text tools update as you type. Reset restores the starting fields.

Larger weights give observations more influence. The weights are normalized by their sum, so weights of 1 and 3 give the same result as 25 and 75.

Must weights total 100?

No. Any positive weights work; only their relative sizes matter.

What assumptions does this tool use?

Weights must be positive and need not be percentages.

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