Average and Standard Deviation Calculator

Average and Standard Deviation Calculator is a free tool that runs entirely in your browser, with no data ever sent to a server. Calculate the mean, median, and standard deviation of a series of numbers.

What it's for

Quickly analyze a series of grades, measurements, or results, without opening a spreadsheet for a simple average or spread calculation.

What this tool does not do

This tool only applies the calculation described, with no check on the context of use. No limit is set by the tool itself; the only constraint is your device's memory.

Frequently asked questions

What's the difference between mean and median?

The mean adds up all the values and divides by their count: an extreme value shifts it strongly. The median is the middle value once the series is sorted: it resists extreme values better.

Is my data sent to a server?

No: the numbers you enter are processed entirely in your browser, on your device. They are never transmitted to a server.

Do I need to create an account or install anything?

No: the tool works directly in this page, with no sign-up and nothing to install.