Standard Deviation Calculator
Calculate the standard deviation and mean of a set of numbers. Enter the values separated by commas to see the population and sample standard deviation.
How it works
Standard deviation measures how spread out the numbers are from the mean. Population deviation divides by N; sample deviation divides by N−1.
σ = √(Σ(x − μ)² ÷ N)Worked examples
Example
For 10, 12, 23, 23, 16 the mean is 16.8 and the population standard deviation is about 5.42.
Frequently asked questions
What is standard deviation?
It measures how much a set of numbers varies from their average — a higher value means more spread.
Population vs sample?
Use population when you have all values; use sample when your numbers are a sample of a larger group (divides by n−1).
What does a high standard deviation mean?
The values are more spread out from the mean; a low one means they cluster close to the average.
Related calculators
Average Calculator
Free average calculator: find the mean, sum and count of a list of numbers in seconds.
EverydayPercentage Calculator
Free percentage calculator: find what X% of a number is, what one number is as a percent of another, and percentage increase or decrease.
EducationGPA Calculator
Free GPA calculator: compute your weighted grade point average on a 4.0 scale by entering your courses and credits.