EXCEL TUTORIAL · FREE TOOLS
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Weighted Average Calculator
Free online tool · No signup · Runs in your browser
Calculate a weighted mean from numeric values and nonnegative weights, with per-row contributions.
Your data stays in this browser tool. No account or upload to a processing service required.
Instructions
- Paste a table with a header and select the value and weight columns.
- Use plain numbers with dot decimals.
- Calculate to see the weighted mean, total weight, weighted sum and each row’s contribution.
- Normalized contributions sum to the weighted mean.
Understanding your result
The sample gives (80×2 + 90×3 + 70×1)/6 = 83.333…. Each row's normalized contribution is part of that final mean. Weights describe relative influence; they need not add to 100, but their total must be positive.
What to do if you have a problem
If calculation fails, check every value and weight for blanks, symbols or negative weights. Use a dot decimal. If the answer surprises you, inspect the largest weights first: they have the greatest influence. Confirm that values share the same units before averaging them.
What to know before using the result
Every value and weight must be finite and numeric; blanks and invalid text are rejected. Negative weights are rejected and total weight must exceed zero. Zero-weight rows contribute zero. Uses JavaScript floating-point arithmetic and is intended for general numerical exploration. Contribution reports accept at most 19,998 data rows so output fits the 20,000-row limit. Input size limit: 2 MB.
These tools work with pasted text or supported CSV files rather than Excel workbook files. CSV exports contain values and do not preserve workbook formatting, formulas or multiple worksheets. Formula builders produce formula text to use in Excel. Data processing runs in the browser tool.
Try an example
Value,Weight 80,2 90,3 70,1
Summary
Use the weighted mean after checking each row's influence and confirming that the values share compatible units.