Standard Deviation Calculator
σ = √(Σ(x − μ)² ÷ N)Mean=30, deviations²=(400+100+0+100+400)=1000, σ=√(1000/5)=√200≈14.14
Free online tool
Standard Deviation Calculator
Enter your data set to find the standard deviation, variance, mean and range.
Instant calculation
Calculate Standard Deviation
Enter your data set.
Your result
Calculation
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Three clear steps
How to use this calculator
- 01
Enter your data
Type your numbers separated by commas.
- 02
Calculate
See population and sample standard deviation, variance and mean.
The formula
How this calculation works
For population: square each deviation from the mean, average them, then take the square root. For sample data, divide by N−1 instead of N.
Check the method
Worked examples
Each example follows the same formula used by the calculator.
Standard deviation of 10, 20, 30, 40, 50?
Mean=30, deviations²=(400+100+0+100+400)=1000, σ=√(1000/5)=√200≈14.14Population SD ≈ 14.14Common questions
Questions about this calculation
What is the Standard Deviation Calculator?
The Standard Deviation Calculator helps you calculate the standard deviation and variance of a set of numbers. Enter your values and select Calculate to get an instant result.
How is the result calculated?
For population: square each deviation from the mean, average them, then take the square root. For sample data, divide by N−1 instead of N.
Can you show an example?
Example: Standard deviation of 10, 20, 30, 40, 50? — Population SD ≈ 14.14.
Is my data saved when I use the Standard Deviation Calculator?
No. All calculations run locally in your browser. Your inputs and results are never uploaded, stored or shared with anyone.
Is the Standard Deviation Calculator free to use?
Yes. The Standard Deviation Calculator is completely free. No account, sign-up or payment is required. It works on mobile, tablet and desktop.
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