Weighted Average Calculator
Compute the weighted average of several values with their weights, showing each value's contribution.
Category: Statistics
About this tool
What Is a weighted average? Weighted Average Calculator. The weighted average calculator combines several numbers into one mean where some count more than others. Each value is multiplied by its weight, the products are added, and the result is divided by the total weight. A plain average treats every value identically. A weighted average applies a weight to each value, so a homework grade worth 20% shapes the final grade less than an exam worth 60%. The formula weights the products rather than the values: sum of (value × weight) divided by sum of weights. When every weight is equal, the weighted average collapses to the ordinary mean. Weighted average = Σ(vᵢ·wᵢ) ÷ Σwᵢ. How to Use Add rows so that each has a value and a weight (positive numbers). Keep adding rows for every component of the average. Read the weighted average, the total weight, and a per-row contribution chart. Worked Example A course has homework 80 with weight 2 and exam 90 with weight 1. The tool computes (80·2 + 90·1) ÷ 3 = 83.33, so the weighted average is 83.33 — higher than 85 would be for equal weights, reflecting the homework's larger weight. Common Use Cases final course grades with percentage weights portfolio returns by asset share survey scores weighted by segment size price indices and composite scores Important Notes Weights can be percentages, shares, or plain counts — the scale does not matter. R