About this tool
Enter value and weight pairs to compute a weighted average, where items with larger weights count more toward the result. It works entirely in your browser and nothing is uploaded.
Type one pair per line as "value, weight". The weighted mean is Σ(valueᵢ × weightᵢ) / Σweightᵢ — the sum of each value times its weight, divided by the total weight. For comparison the tool also shows the simple (unweighted) average, which treats every value equally, along with the total weight and the sum of value × weight.
It is perfect for grade or GPA calculations, weighted scores, blended interest rates or any mix where some numbers should count more than others. The total of all weights must be greater than zero.
Frequently asked questions
How do I enter the data?
Put one pair per line as value then weight, separated by a comma or space, for example "90, 3". Lines without two numbers are ignored.
How is the weighted average calculated?
It multiplies each value by its weight, adds those products, and divides by the sum of the weights: Σ(value × weight) / Σweight.
Why show the simple average too?
The simple (unweighted) average treats every value equally, so comparing it with the weighted result shows how much the weights shift the outcome.
Can weights be zero or decimals?
Weights can be decimals and individual weights can be zero, but the total of all weights must be greater than zero, otherwise the input is invalid.