Exceljet

Quick, clean, and to the point

Square root of number

Excel formula: Square root of number
Generic formula 
=SQRT(number)
Summary 

To calculate the square root of a number in Excel, you can use the SQRT function. In the example shown, the formula in C5 (copied down) is:

=SQRT(B5)

The result is the square root of each number in column B.

Explanation 

The SQRT function is fully automatic and will return the square root of any positive number. For example, to get the square root of 25, you can use:

=SQRT(25) // returns 5

To get the square root of 16:

=SQRT(16)  // returns 4

To get the square root of a number in cell A1:

=SQRT(A1) // square root of A1

Negative numbers

If you give SQRT a negative number, it returns a #NUM! error:

=SQRT(-4) // returns #NUM!

To use the SQRT function with negative numbers you nest the ABS function inside SQRT like this:

=SQRT(ABS(-4)) // returns 2

The ABS function converts the negative number to a positive number and returns the result to the SQRT function, which calculates a final result.

Exponent operator (^)

Another way to get the square root of a number in Excel is to use the exponent operator , the caret (^). To return the square root of a number in A1, you can use a formula like this:

=A1^(1/2) // square root

The screen below shows how this formula looks in a worksheet:

Square root of number with exponent

Nth root

Excel does not have a built-in function to get the nth root of a number. However, you can calculate the nth root of a number by raising the number to the power of 1/n:

=A1^(1/n) // nth root

The screen below shows this formula in use:

Calculate nth root of a number

Square root with POWER

You can get also get the square root or nth root of a number with the POWER function.  POWER is a general function for raising a number to a given power, for example:

=POWER(2,2) // returns 4
=POWER(2,3) // returns 8
=POWER(2,4) // returns 16

The general form for getting the nth root with POWER is:

=POWER(A1,1/n) // nth root

For example:

=POWER(A1,1/2) // square root
=POWER(A1,1/3) // cube root
=POWER(A1,1/4) // fourth root

The screen below shows how the POWER function can be used to calculate square root of the numbers in column A:

Square root of number with POWER function

Author 
Dave Bruns

Excel Formula Training

Formulas are the key to getting things done in Excel. In this accelerated training, you'll learn how to use formulas to manipulate text, work with dates and times, lookup values with VLOOKUP and INDEX & MATCH, count and sum with criteria, dynamically rank values, and create dynamic ranges. You'll also learn how to troubleshoot, trace errors, and fix problems. Instant access. See details here.

Download 100+ Important Excel Functions

Get over 100 Excel Functions you should know in one handy PDF.