Standard Deviation Calculator
Calculate the standard deviation of a set of numbers. Paste or type your values and choose sample or population, and the calculator returns the standard deviation, the variance, the mean, the count and the sum. It updates as you edit the list.
Standard deviation
2.1381
Count8
Mean5
Variance4.5714
Sum38
How it works
Standard deviation measures how spread out numbers are around the mean. First find the mean, then the average of the squared differences from the mean (the variance), then take its square root. The sample version divides by n − 1, while the population version divides by n.
Frequently asked questions
What is the difference between sample and population?
Use population when your data is the entire group. Use sample when it is a subset used to estimate a larger group; it divides by n minus 1 to correct for bias.
What does a higher standard deviation mean?
A higher value means the data points are more spread out from the mean, while a lower value means they cluster closely around it.
Does it also show variance?
Yes. Variance is shown alongside the standard deviation, the mean, the count and the sum.