Standard Deviation Calculator

Standard deviation tells you how spread out a set of numbers is: a small value means the numbers sit close to the average, a large one means they vary widely. Paste your data separated by commas, spaces or new lines and the calculator returns the standard deviation and variance along with the mean, median, mode, range and other summary statistics.

How to use Standard Deviation Calculator

1. Paste or type your numbers. Commas, spaces, tabs and new lines all work, so you can paste a spreadsheet column.
2. Choose Sample if the numbers are a sample of a bigger group, or Population if they are the whole group.
3. Read the results; they update as you edit the numbers.

When it comes in handy

• Statistics homework and checking hand calculations.
• Seeing how consistent response times, prices or test scores are.
• Quick summary statistics without opening a spreadsheet.

Frequently asked questions

Sample or population?

Use population when you have every value of the group you care about (all 30 students in a class). Use sample when your numbers are a subset used to estimate a larger group; it divides by n − 1, which gives a slightly larger, unbiased estimate.

What is the relationship between variance and standard deviation?

The standard deviation is the square root of the variance. It is in the same units as your data, which makes it easier to interpret.