Standard Deviation Calculator
Paste a dataset to calculate population or sample standard deviation, variance, mean and quartiles. Each deviation and squared deviation is visible in a table, with a histogram and CSV export for checking the arithmetic.
Your result
How the calculation works
Mean=Σx/n. Squared-deviation sum=Σ(x−mean)². Population variance divides by n; sample variance divides by n−1. Standard deviation is the square root of variance.
Worked example
For 2,4,4,4,5,5,7,9, the mean is 5, population variance is 4 and population standard deviation is 2. Sample variance is 32/7, with standard deviation approximately 2.13809.
Assumptions and limitations
Accepts 2–2,000 finite values. Quartiles use linear interpolation at (n−1)p. Histogram uses equal-width bins, with the last upper edge included. No weights, missing-value imputation or outlier removal.
Choose population only when describing the full population of interest. Sample correction does not by itself fix biased sampling or make a nonrepresentative dataset representative.
Sources and editorial responsibility
Maintained by Renvoro Pty Ltd. Sources inform the methods and assumptions shown here; outputs have the limitations described on this page.
Method reviewed 2026-10-13. Calculation standards · Report an issue