Weighted average calculator
Combine numbers that do not count equally, such as test scores worth different shares of a grade or prices paid for different amounts. Each value is multiplied by its weight, so heavier items pull the result more.
- Runs in your browser
- Free, no account needed
- Copy or download the result
Result
Example
80:2 90:3 100:1
Pairs: 3 Total weight: 6 Weighted average: 88.3333333333
How to use the weighted average calculator
- Type one value:weight pair per line, such as 80:2, 90:3 and 100:1 on separate lines.
- You can also separate pairs with commas or semicolons, and use a space instead of the colon, as in 80 2.
- Press Run to see Pairs, Total weight and Weighted average.
- Press Copy result or Download to save it.
How it works
Weighted average = sum of (value x weight) / sum of weights. For 80:2, 90:3, 100:1 that is 530 / 6, shown as 88.3333333333.
Weights can be any nonnegative numbers, such as credit hours, percentages or counts. They do not need to add up to 1 or 100.
A negative weight is rejected, and at least one weight must be greater than zero.
Accepts up to 5,000 pairs. Values may be negative. Results use floating point math, shown to 12 significant digits.
Everything runs in your browser. Your input is not uploaded or stored.
Questions and answers
How do you calculate a weighted average?
Multiply each value by its weight, add the products, then divide by the total of the weights.
How do I calculate my grade with weighted categories?
Enter each category score with its weight, such as 85:40 for tests worth 40% and 92:60 for homework worth 60%. The result is 89.2.
Do the weights have to add up to 100?
No. The tool divides by whatever the weights add up to, so weights of 2, 3 and 1 give the same answer as 20, 30 and 10.
What happens if a weight is zero?
That value has no effect on the result, though it still counts as a pair. At least one weight must be positive.