Weighted Average Calculator
A weighted average is an average where each value is given a weight representing its relative importance. Unlike a simple average where all values contribute equally, a weighted average allows you to emphasize certain values more than others. The formula is: (sum of value × weight) / (sum of weights). This calculator lets you enter pairs of values and weights, up to 10 rows, and automatically computes the weighted average. You can also add and remove rows as needed. Weighted averages are essential in grade calculations, investment analysis, and any situation where different data points have different levels of importance.
Weighted average formula
Weighted average = (sum of value × weight) / (sum of weights)
Example: (85 × 0.4 + 92 × 0.6) / (0.4 + 0.6) = 89.4
Common weighted average examples
| Context | Values | Weights | Result |
|---|---|---|---|
| Grade (midterm 40%, final 60%) | 85, 92 | 0.4, 0.6 | 89.4 |
| Course GPA (3 credits, 4 credits) | 3.5, 3.8 | 3, 4 | 3.67 |
| Portfolio return (40%, 60%) | 5%, 8% | 0.4, 0.6 | 6.8% |
Weighted average calculator: frequently asked questions
What is a weighted average?
A weighted average is an average where different values have different levels of importance (weights). The formula is: (sum of value × weight) / (sum of weights). For example, if a final grade is 40% midterm, 60% final, the weighted average would be (midterm × 0.4 + final × 0.6).
When should you use a weighted average?
Use weighted averages when different values should be counted with different importance. Examples include calculating grade point averages (different credits for different courses), investment returns (different amounts invested), or portfolio performance (different asset weights).
What happens if weights do not add up to 1?
The calculator always divides by the sum of all weights, so the weights do not have to add up to 1 or 100. You can use any relative weights you want. For example, weights of 2 and 3 are equivalent to 0.4 and 0.6.
Can weights be negative?
While mathematically possible, negative weights are uncommon. Negative weights would reduce the overall average, which might represent a deduction or penalty. Most practical applications use positive weights.
How is weighted average different from simple average?
In a simple average, all values have equal weight (weight = 1). In a weighted average, values can have different weights. For example, the simple average of 10 and 20 is 15. The weighted average of 10 (weight 1) and 20 (weight 3) is (10×1 + 20×3) / 4 = 17.5.
Official sources
- Weighted average: NIST Special Publication 330.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.