How it works
Add all numbers, then divide by how many numbers you entered. Each value has equal weight. For 10, 20, 30, 40 and 50, the sum is 150 and the mean is 30.
Mean = sum of values / number of values
Worked example
Show example inputs and result
Numbers: 10 20 30 40 50.
- Arithmetic mean
- 30
- Sum
- 150
- Count
- 5
Questions and answers
Is this a weighted average?
No. Each entry counts once. If observations have different weights, use a weighted-average calculation instead. Zero values are included; blank entries are not numbers.
Why are some results rounded?
Results display up to 8 decimal places. Calculations use the unrounded values; very small values use scientific notation. JavaScript floating-point arithmetic can introduce tiny rounding differences.
Are my inputs sent to a server?
The calculator processes inputs in your browser. Its code does not send your values to a server.
Method reviewed: October 8, 2026 · Methods & accuracy