Weighted Average Calculator
Calculate a weighted mean from value and weight pairs.
What is Weighted Average?
A weighted average counts each value in proportion to a weight rather than treating them all equally — a course grade where the final exam is 40% of the mark, a portfolio where holdings differ in size. When every weight is the same it collapses to the ordinary mean, which is the useful sanity check, so both are shown.
How it works
Each line is parsed as a value and a weight, so a column pair copied out of a spreadsheet pastes in as-is. The total weight normalises the sum, which means weights can be percentages, counts or decimals without the user converting anything first. Weights that sum to zero are reported as what they are — a division by zero, not a zero average.
- Enter your input. Type or paste your input into the field above — the tool responds instantly.
- Review the result. Output updates live as you type. Everything runs entirely in your browser.
- Copy or download. Use the Copy button to grab the result, or Download to save it as a file.
Examples
Realistic sample
Type or paste any realistic input — the tool computes the result locally and instantly.
Common mistakes
Expecting a server round-trip
Nothing is uploaded — every tool in this category runs entirely in your browser.