Standard Deviation Calculator

Calculate standard deviation, variance, mean, median, and mode from a set of numbers

mean
18
median
18.5
mode
23
standardDeviation
4.898979
variance
24
count
8
sum
144
range
13

Frequently Asked Questions

What is the difference between population and sample standard deviation?

Population standard deviation divides by N (total count), while sample standard deviation divides by N-1 (Bessel's correction). Use sample when working with a subset of data.

What does standard deviation tell us?

Standard deviation measures how spread out numbers are from the mean. A low value means data points cluster near the mean, while a high value means they are more spread out.

What is variance?

Variance is the square of the standard deviation. It represents the average of the squared differences from the mean.