Weighted Average Calculator
Add any set of values with their corresponding weights to calculate the weighted average — useful for anything from investment portfolio returns to survey ratings to blended prices.
How the Weighted Average formula works
The general weighted average formula:
Weighted average = Σ(value × weight) / Σ(weight)
Step-by-step calculation
- Multiply each value by its corresponding weight.
- Sum all of those weighted values.
- Sum all the weights.
- Divide the total weighted sum by the total weight.
Worked example
Three investments: 8% return on $5,000, 4% return on $3,000, and 12% return on $2,000: Weighted average return = (8×5,000 + 4×3,000 + 12×2,000) / (5,000+3,000+2,000) = (40,000+12,000+24,000)/10,000 = 7.6%.
Frequently asked questions
How is this different from a simple average?
A simple average treats every value equally, while a weighted average lets some values count more than others based on their assigned weight — essential whenever the items being averaged aren't equally significant, like account balances of different sizes or exam scores of different importance.
Do weights need to add up to any particular number?
No — since the formula divides by the total weight, weights can be in any units (dollars, percentages, counts) and don't need to sum to 100 or 1.