Free online standard deviation calculator. Enter data to compute mean, variance, standard deviation (sample/population), min, and max. Pure frontend, no data upload.
Standard deviation measures how spread out data points are from the mean. A larger standard deviation means more dispersed data; a smaller one means data is more concentrated. It is the square root of the average of squared deviations from the mean.
Population standard deviation divides by n (total count), used when you have all data. Sample standard deviation divides by n-1 (Bessel's correction), used when estimating from a sample. Most real-world applications use sample standard deviation.
Variance is the average of squared deviations from the mean. Standard deviation is the square root of variance. Standard deviation has the same unit as the original data, making it easier to interpret.
Comma-separated (12, 15, 18), space-separated (12 15 18), and newline-separated data are all supported. The tool automatically parses various formats and filters invalid entries.
No. All calculations happen locally in your browser. Data is never uploaded to any server. This is a pure frontend tool that fully protects your data privacy.