Weighted Average Calculator
Combine values with different weights, perfect for grades and portfolio returns.
Weighted Average Calculator
Combine values with different weights, perfect for grades and portfolio returns.
How to use the Weighted Average Calculator
- Enter values separated by commas.
- Enter corresponding weights separated by commas.
- Click Calculate.
Formula
Weighted average = Σ(value × weight) / Σ(weight)
Example
Grades: 92 (weight 40%), 85 (weight 35%), 78 (weight 25%). WA = 86.3.
Step-by-step calculation
- Multiply: 92×40=3680, 85×35=2975, 78×25=1950.
- Sum products: 3680+2975+1950 = 8605.
- Sum weights: 40+35+25 = 100.
- Weighted average: 8605 ÷ 100 = 86.05.
Real-world uses
- Grade point average calculation.
- Portfolio return calculations.
- Survey result analysis.
Common mistakes
- Entering a different number of values and weights.
- Using weights that sum to zero.
- Treating weighted average as a simple average when weights differ significantly.
Frequently asked questions
Do weights need to add up to 100?
No. The formula divides by the sum of weights, so any consistent scale works.
What if all weights are equal?
The weighted average equals the simple arithmetic mean.
Can weights be negative?
Mathematically yes, but in most real applications weights are positive.