Weighted Average Calculator

Enter the values in one box and their weights in the other, in the same order. Weights can be percentages, credits, quantities or counts.

Values and weights

Separate numbers with commas, spaces or new lines.

One weight per value, in the same order.

Weighted average83.6
Sum of weights
100
Unweighted average
82.3333333333

Working

  1. Multiply each value by its weight and add: 85×20 + 72×30 + 90×50 = 8,360
  2. Divide by the total weight: 8,360 ÷ 100 = 83.6

Formula

weighted average = Σ(w × x) ÷ Σw

x
each value
w
the weight of that value

Worked example

Scores 85, 72, 90 weighted 20%, 30%, 50%

  1. Multiply: 85 × 20 = 1,700; 72 × 30 = 2,160; 90 × 50 = 4,500
  2. Add the products: 8,360
  3. Add the weights: 100
  4. Divide: 8,360 ÷ 100 = 83.6

The weighted average is 83.6 (the plain average would be 82.33).

Common uses

  • Course grades where exams, coursework and quizzes count differently.
  • The average price paid when buying different quantities at different prices.
  • Combining the averages of groups of different sizes: weight each group’s mean by its size.