About the Standard Deviation Calculator
Find the standard deviation, variance and mean of a list of numbers. This tool is free, works in your browser and needs no sign-up.
How to use the Standard Deviation Calculator
Type or paste your numbers separated by commas, spaces or new lines.
Formula used
Population SD = √(Σ(x − mean)² ÷ n). Sample SD = √(Σ(x − mean)² ÷ (n − 1)).
Frequently asked questions
Is the Standard Deviation Calculator free to use?
Yes. It is completely free and you can use it as many times as you like.
How accurate is the Standard Deviation Calculator?
The calculator uses standard formulas, so the maths is exact. Real life results can differ because of fees, taxes, rounding or personal factors, so treat the answer as an estimate.
Do you store the numbers I enter?
No. All calculations run in your browser. The values you type are not sent to our server.
Disclaimer: results are estimates for information only. They are not financial, medical or professional advice.