Weighted Average Calculator
Σ(value × weight) / Σ(weight). Click any i for detail.
Values & weights
Rows
i
List
One per line: value weight (e.g. 88 0.4 or 88 40%). |
|---|
How to use this calculator
- Enter one value and weight per line.
- Weights can be percents (40%) or decimals (0.4).
- Read the weighted mean and total weight.
- Check that high-weight rows pull the average as expected.
Results explained
Each value contributes in proportion to its weight. Weights do not need to sum to 100 if they are relative. Equal weights reduce to a simple mean.
Quick reference: weighted mean
Weights can be percents or any positive numbers.
| Item | Detail |
|---|---|
| Formula | Σ(value × weight) / Σ(weight) |
| Percents | 40% and 0.4 both work |
| Equal weights | same as simple average |
| Zero weight | row ignored |
GPA pages treat credit hours differently from generic weights.
How the estimate is built
weighted avg = Σ(vᵢ·wᵢ) / Σ(wᵢ).
Example scenario
88@40% + 92@25% + 75@20% + 100@15% → about 87.9.
FAQ
Must weights sum to 100?
No, as long as they are relative. 4:2:1 gives the same mean as 40:20:10.
How is this different from GPA?
GPA maps letter grades to points and uses credit hours. This page takes numeric values directly.
Can weights be zero?
A zero-weight row does not affect the mean.