AI Math SolverA standard deviation calculator measures how spread out a data set is around its mean. Enter your values to get the standard deviation, variance, and mean in one pass.
Standard deviation is the square root of the average squared distance of each point from the mean. It is the single most common measure of spread in statistics.
Subtract the mean from each value, square the differences, average them to get the variance, then take the square root. The calculator lays out each stage and offers both sample and population versions.
Standard deviation measures how spread out values are around the mean. A small value means the data clusters tightly; a large value means it is scattered.
Use the population formula (dividing by n) when your data is the entire group, and the sample formula (dividing by n − 1) when it is a sample drawn from a larger population.