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Standard Deviation Calculator is a free online tool that computes the population standard deviation, sample standard deviation, mean, and count from a list of numbers. Enter numbers separated by spaces or commas for instant results.

Standard deviation measures how spread out numbers are from their mean. A low standard deviation means values are close to the mean; a high value means they are spread out. It is a fundamental statistic used in data analysis, finance, science, and quality control.

Standard Deviation Calculator

Calculate the standard deviation of a list of numbers.

How to Use

  1. Enter your numbers separated by spaces or commas in the input field
  2. Click the Calculate button
  3. The tool will display the mean, population std dev, sample std dev, and count
  4. Copy the results as needed

Example

Input

2 4 4 4 5 5 7 9

Output

Mean: 5
Std Dev (Population): 2
Std Dev (Sample): 2.138
Count: 8

FAQ

What is the difference between population and sample standard deviation?
Population std dev divides by N (all data points). Sample std dev divides by N-1 (Bessel's correction) and is used when the data is a sample of a larger population.
Is this tool free?
Yes, it is completely free with no registration required.
Does this tool run in the browser?
Yes, all calculations happen locally in your browser with no data sent to a server.

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