ToolNest

Weighted Average Calculator

Average with weightsRuns locally · nothing uploaded

ValueWeight
Weighted average
87.1
Total weight
100
Unweighted mean
85
Also works as:weighted mean calculatorweighted gradeweighted average cost

How it works

When to use it

  • Average grades by credit hours.
  • Find the average cost across purchases of different quantities.
  • Score options against weighted criteria.

Formula

Weighted average = Σ(value × weight) ÷ Σweight

Worked example

Given: 80 (weight 2), 90 (weight 3)

  1. (80 × 2 + 90 × 3) ÷ 5 = 86.
  2. Simple mean = 85.

Result: 86, one point above the simple mean because the heavier item scored higher.

Reading the result

  • Weights can be percentages, credits or quantities; they don't need to sum to 1 or 100.

Limitations

  • Undefined when all weights are 0.

How to use

  1. 1Enter a value and its weight on each row.
  2. 2Add more rows as needed.
  3. 3The weighted average updates instantly.

FAQ

What is the weighted average formula?

Weighted average = Σ(value × weight) ÷ Σ(weight). Weights can be percentages, credits, quantities, etc.

Do the weights have to add up to 100?

No. The formula divides by the total weight automatically.