Statistics
Standard Deviation Calculator
Use this standard deviation calculator to measure how spread out a data set is around its mean.
Separate numbers with commas, spaces, or semicolons.
Standard deviation
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- Variance
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- Mean
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- Count
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Study path
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What the standard deviation calculator solves
Use this standard deviation calculator to measure how spread out a data set is around its mean.
Formula
How to use it
- Enter a list of numbers.
- Choose sample or population.
- Read standard deviation, variance, mean, and count.
How to read the answer
A larger standard deviation means values are more spread out from the mean.
Common mistakes and edge cases
- Use sample standard deviation when your data is a sample from a larger population.
- Sample standard deviation needs at least two values.
- Outliers can strongly affect standard deviation.
Worked examples
Sample data
Standard deviation
4.3704
Population data
Standard deviation
2
Frequently asked questions
Should I use sample or population?+
Use sample when the data represents part of a larger group. Use population when the data includes every value you care about.
What is variance?+
Variance is the average squared distance from the mean. Standard deviation is the square root of variance.
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Last updated: May 8, 2026