Weighted Average Calculator

Calculate a weighted average from a list of values and weights. Add your values to see the weighted average, the total weight and a contribution breakdown.

Add a row for each value with its weight. The calculator returns the weighted average, the total weight and the number of items, with a breakdown of each item's contribution in the summary.

ValueWeight
Weighted average
Total weight
Items

A weighted average accounts for the different importance (weight) of each value, so heavier items pull the average more than lighter ones — essential for grades, surveys and portfolio returns.

The maths

Weighted average = sum(value × weight) ÷ sum(weights)

Each item's contribution = (its weight ÷ total weight) × 100% of the result. A simple average is just the weighted average where every weight is equal.

Examples

  • Values 80 (w25) and 90 (w75) = 87.5
  • The 90 carries three times the pull of the 80
  • Equal weights give the same result as a normal average

Frequently asked questions

What if a weight is zero?

That item is ignored, since a zero weight contributes nothing. Make sure at least one item has a positive weight.

How is this different from a normal average?

A normal (arithmetic) average treats every value equally. A weighted average lets some values count more — the right choice when items differ in importance, size or credit hours.

Just for the giggles, much love.
linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram