To calculate standard deviation, paste your numbers and choose sample or population; the calculator returns the standard deviation, variance and mean. Use population when your list is the whole group and sample when it is a subset.
How to use the Standard Deviation Calculator
- Paste your list of numbers.
- Choose sample or population.
- Read the standard deviation, variance and mean.
- Compare against another data set if needed.
Worked example
For the population 2, 4, 4, 4, 5, 5, 7, 9 the mean is 5, the variance is 4 and the population standard deviation is 2.
Tips and common mistakes
- Sample standard deviation divides by n minus 1, so it is slightly larger than the population value.
- A small standard deviation means values cluster near the mean.
- Standard deviation is in the same units as your data; variance is in squared units.
Frequently asked questions
Sample or population?
Use population if you have every value in the group, and sample if your data is a subset used to estimate a larger group.
What is variance?
The average of the squared distances from the mean. The standard deviation is its square root.
Is it private?
Yes. It is calculated in your browser.