σ Standard Deviation Calculator

Understanding Standard Deviation

Standard deviation measures the amount of variation or dispersion in a set of data values. A low standard deviation means data points cluster close to the mean, while a high standard deviation indicates data is spread out over a wider range.

Population vs Sample

• Population (σ): Use when your data represents the entire population. Divides by N.
• Sample (s): Use when your data is a sample from a larger population. Divides by N-1 (Bessel's correction) to provide an unbiased estimate.

Standard deviation is widely used in statistics, quality control, finance (measuring volatility), and science to quantify uncertainty and variability in data.