Standard Deviation Calculator

Compute sample and population standard deviation, variance, and mean.

šŸ’” Quick Answer & Definition(Verified Formula)

Compute sample and population standard deviation, variance, and mean.

Sample vs. Population Standard Deviation

Population standard deviation (Ļƒ) divides by N for complete datasets. Sample standard deviation (s) uses Bessel's correction dividing by Nāˆ’1 for statistical samples.

Variance and Sum of Squares

Variance is standard deviation squared. The calculator displays step-by-step deviations from the mean and total sum of squared differences.

Empirical Rule (68-95-99.7 Rule)

In a normal distribution, ~68% of data falls within 1 standard deviation of the mean, ~95% within 2 deviations, and ~99.7% within 3.

100% Free, Instant & Private. All computations run directly in your browser sandbox without sending personal data to any external server.