Standard Deviation Calculator
Calculate the standard deviation of a dataset — a measure of how spread out its values are.
Calculate
Enter your values below.
Result
Standard deviation
0
Formula used
Standard deviation is the square root of variance, expressed in the same units as the original data.
Example: 2, 4, 4, 4, 5, 5, 7, 9 (sample) → standard deviation ≈ 2.14.
How to use this calculator
- Enter Numbers (comma-separated).
- Choose Dataset type.
- Press Calculate to see your result instantly.
FAQ
Frequently asked questions
What does standard deviation tell you?
How much, on average, individual values differ from the mean — a low value means data is tightly clustered.
Sample or population — which do I need?
Use sample if your numbers are a subset of a larger group you're estimating about; population if they are the complete group.
Can standard deviation be negative?
No, it's always zero or positive, since it comes from a square root.
How is this related to variance?
Standard deviation is simply the square root of variance.