Standard Deviation Calculator

Calculate the standard deviation, variance, mean, median, mode, range and quartiles of a data set, for samples and populations.

Frequently asked questions

What does standard deviation tell you?

How spread out the values are around the mean. In a normal distribution, about 68% of values lie within one standard deviation.

How are quartiles calculated?

By linear interpolation between ranks, the same method as Excel's QUARTILE.INC.