# A to Z of Excel Functions: the DEVSQ Function

23 July 2018

*Welcome back to our regular A to Z of Excel Functions blog. Today we look at the DEVSQ function. *

**The DEVSQ function**

This function returns the sum of squares of deviations of data points from their sample mean. This is a key component of such statistical calculations as standard deviation.

The **DEVSQ **function employs the following syntax to operate:

**DEVSQ(number1, [number2], ...)**

The **DEVSQ** function has the following arguments:

**number1, number2, ...:****number1**is required, subsequent numbers are optional. You may have between one and 255 arguments for which you want to calculate the sum of squared deviations. You can also use a single array or a reference to an array instead of arguments separated by commas.

It should be further noted that:

- arguments can either be numbers or names, arrays, or references that contain numbers
- logical values and text representations of numbers that you type directly into the list of arguments are counted
- if an array or reference argument contains text, logical values, or empty cells, those values are ignored; however, cells with the value zero are included
- arguments that are error values or text that cannot be translated into numbers cause errors
- the equation for the sum of squared deviations is:

Please see my example below:

*We’ll continue our A to Z of Excel Functions soon. Keep checking back – there’s a new blog post every business day.*

*A full page of the function articles can be found here. *