About this calculator
Enter each value and its weight.
How to use it
- Enter each value.
- Enter its weight.
- Read the weighted average.
The formula
Weighted average = Σ (value × weight) ÷ Σ weight
- weight
- how much each value counts
Worked example
Values 80, 65 and 90 with weights 3, 2 and 5
- Σ value × weight = 240 + 130 + 450 = 820.
- Σ weights = 10; weighted average = 82.
What the result means
A simple average is a weighted average with equal weights.
Assumptions
- Non-negative weights.
Limitations
- At least one weight must be above zero.
Frequently asked questions
How is a weighted average different from a simple average?
Values with larger weights count more.
Do weights need to add to 100?
No.
Can I use it for stock prices?
Yes: price as value, quantity as weight.
Last reviewed on 3 October 2026. Found a mistake? Tell us.