Standard Deviation Calculator

Calculate standard deviation, variance, mean, and other statistics for a data set

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Enter numbers (comma, space, or newline separated)

Count (n)

Mean

Median

18.5

Std Dev (σ)

4.898979

Std Dev (s)

5.237229

Variance (σ²)

Variance (s²)

27.428571

Sum

144

Range

Min

Max

Frequently Asked Questions

What is standard deviation?▼

Standard deviation measures how spread out numbers are from the mean. A low SD means data points cluster near the mean; high SD means they're spread out.

Population vs sample standard deviation?▼

Population SD divides by N, sample SD divides by N-1 (Bessel's correction). Use sample SD when your data is a subset of a larger population.

How to Use Standard Deviation Calculator

1Open the Standard Deviation Calculator tool above - it loads instantly in your browser.
2Enter your data or upload your file. Everything is processed locally on your device - nothing is uploaded to any server.
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