Case 1
- First value
- 80
- Weight of the first value
- 3
- Second value
- 90
- Weight of the second value
- 1
82.5000
Open with these valuesWeighted Average Calculator
82.5000
Result: 82.5000Multiply each value by its weight, add the two products, divide by the weights added together. A score of 80 weighted 3 and a score of 90 weighted 1 give 330 ÷ 4 = 82.5. Only the ratio of the weights matters: 3 and 1 give the same answer as 30 and 10.
Worked examples
Case 2
- First value
- 85
- Weight of the first value
- 4
- Second value
- 95
- Weight of the second value
- 2
88.3333
Open with these valuesCase 3
- First value
- 100
- Weight of the first value
- 1
- Second value
- 50
- Weight of the second value
- 1
75.0000
Open with these valuesHow it's calculated
Weighted average = (v₁ × w₁ + v₂ × w₂) ÷ (w₁ + w₂)
- StepEnter the first value and how much it counts.
- StepEnter the second value and its weight.
- ResultRead the average, pulled toward the value with the larger weight.
Reference table
| v₁, w₁, v₂, w₂ | Total weight | Weighted average |
|---|---|---|
| 0, 1, 100, 1 | 2 | 50 |
| 100, 1, 50, 1 | 2 | 75 |
| 60, 5, 80, 5 | 10 | 70 |
| 70, 2, 90, 3 | 5 | 82 |
| 80, 3, 90, 1 | 4 | 82.5 |
| 85, 4, 95, 2 | 6 | 88.3333 |
| 12.5, 2, 7.5, 0 | 2 | 12.5 |
Questions
How do I calculate a weighted average?
Multiply each value by its weight, add the products, and divide by the total weight: (v₁ × w₁ + v₂ × w₂) ÷ (w₁ + w₂). A score of 80 weighted 3 and a score of 90 weighted 1 give (240 + 90) ÷ 4 = 82.5.
What is a weighted average?
It is an average where each value counts according to its weight rather than equally. Values with a larger weight pull the result toward themselves, which is why a final exam worth three times a quiz dominates the overall grade.
How is it different from a normal average?
A normal average treats every value equally, a weighted average lets some count more. When the weights are equal the two are identical — 60 and 80 with weights 5 and 5 give 70, exactly the plain average. The difference only appears once the weights differ.
What numbers should I use for the weights?
Any non-negative numbers that reflect how much each value should count: percentages such as 60 and 40, credit hours, or plain multipliers like 3 and 1. Only the ratio between them matters, so 3 and 1 give the same answer as 30 and 10.
How do I use this for grades?
Enter each grade as a value and its course weighting as the weight. If the exam is worth 70 percent and coursework 30, put the exam grade with weight 70 and the coursework grade with weight 30. The result is the overall weighted grade.
Can the weights be zero?
A single weight can be zero, which simply drops that value: 12.5 weighted 2 against 7.5 weighted 0 returns 12.5. If both weights are zero there is nothing left to weight, and the calculator falls back to the plain average of the two values.
Sources and last check
Information, not professional advice.