Statistics Calculator
A collection of basic statistics calculators such as mean and standard deviation.
Standard Deviation Calculator
Enter comma-separated numbers to calculate the mean and population standard deviation.
Read MoreAbout This Category
Two summaries answer most questions about a set of numbers: where the middle is, and how far the values spread. The average gives the first; the standard deviation gives the second, and without it an average can be actively misleading.
The pages label whether they compute a population or a sample standard deviation, since they differ by the divisor (n versus n − 1) and by roughly 2 % at twenty observations.
Frequently Asked Questions
When should I use the median instead of the mean?
When the data is skewed or has outliers. A single very large value drags the mean up but leaves the median unchanged, so income and house prices are usually reported as medians.
What does one standard deviation contain?
About 68 % of a normal distribution; two contain roughly 95 %. That interpretation assumes a roughly bell-shaped distribution, which should be checked.
Population or sample?
Sample, if the numbers are a subset used to estimate something larger. Population, only if the set is complete.
Calculators in This Category
Sources & last update
2026-10-19