How to use the Standard Deviation Calculator
The standard deviation calculator shows how spread out a set of numbers is.
Open the Standard Deviation Calculator →
What you need to enter
- Numbers (separated by commas or spaces)
The formula
Population σ = √(Σ(x − mean)² ÷ n). Sample s = √(Σ(x − mean)² ÷ (n − 1)).
Worked example
Using the default values in the calculator:
- Numbers (separated by commas or spaces): 12, 15, 18, 22, 22, 30
| Sample standard deviation (s) | 6.33772 |
| Population standard deviation (σ) | 5.78552 |
| Mean | 19.83333 |
| Sample variance | 40.16667 |
| Population variance | 33.47222 |
| Count | 6 |
| Sum | 119 |
Tips for better results
- Use the sample version when your data is a sample.
- Compare with the mean.
Common mistakes to avoid
- Using the wrong version.
- Entering text.