The Excel SQRT function is a Math and Trigonometry formula that can calculate and return the positive square root of the input value. This is essentially the formula approach to finding square root of a number in Excel. For other methods and finding different exponents, please see: How to find square root in Excel. In this guide, we’re going to show you how to use the Excel SQRT function to find the square root of a number, and also go over some tips and error handling methods.

Supported versions

  • All Excel versions

SQRT Function Syntax



number The numeric value for which you want to find the square root. Note that this must be a positive number, otherwise you will get an error.


The SQRT function only requires a single argument (number) to find the square root of a number. Please note that you need to enter a positive number for the number argument for the function to work as intended, and you will get an error otherwise. Here, you can use a static value, a cell reference, or the result of another formula. Below is a set of examples on how to use the formula with different input values.

Excel SQRT Function 01

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  • If you want to use a negative number, use the ABS function in combination to make the input value an absolute number, and ignore its sign:


  • Alternatively, you can use rational exponents to calculate the square root of a number. For example, if the number is x, the formula would be something like below,



  • The SQRT function will return a #NUM! error if the number argument is negative.