How to Calculate Cube Root in Excel

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- Written by Puneet

For Example – A construction manager needs to determine the size of a cubic container that can hold a specific volume of material. By calculating the cube root of the volume in cubic feet, they can quickly find the length of each side of the cube, ensuring they choose the suitable container for storage or transport.

What is CUBE ROOT?

The cube root is a value that, when multiplied by itself three times, equals the original number. For example, the cube root of 27 is 3 because 3×3×3=27. You can calculate the cube root in Excel using the POWER function with 1/3 as the exponent (e.g., =POWER(27, 1/3)) or the caret operator (e.g., = 27 (1/3)).

In this tutorial, you will will learn both of these methods. And in the end, I have shared code to create a custom function for a cube root.

POWER Function for Cube Root Formula

In Excel, the POWER function raises one number to the power of another. For example, To find the cube root, you can use =POWER(number, 1/3), which means you’re raising the number to the power of one-third.

You need to specify the number for which you want to find the cube root, and for the second argument, you need to specify the power to calculate the cube root (1/3).

=POWER(A1,1/3)

In the following example, we have a number (125) in cell A1, and in cell B1, we have a formula that returns a cube root of 125 as the result.

power-function-for-cube-root

You can see that we have used 1/3 in the power argument, not 3, so that’s one thing that you need to take care of while writing this formula.

And, if you want to calculate a cube root of a number that is a negative number, you simply need to follow the same function.

Cube Root with CARET Operator (^)

Just like, POWER, in Excel, the caret (^) operator is used for exponentiation, meaning it raises a number to the power of another number. With the CARET operator, you don’t need to use a function to create a formula.

=A1^(1/3)
  1. First, enter “=” in a cell.
  2. Then, specify the number for which you want to calculate the cube root.
  3. Next, enter the “^” caret operator.
  4. In the end, use the “(1/3)” as a power, but make sure to wrap it in parentheses.
cube-root-with-caret-operator

The formula =A1^(1/3) calculates the cube root of the value in cell A1.

Create a Custom Function for Cube Root

If you are familiar with VBA, you can use the code below to create a custom function to get the cube root of a number in Excel.

Function CubeRoot(num As Double) As Double
    CubeRoot = num ^ (1 / 3)
End Function
=CubeRoot(A1)

You can use this function in Excel by typing =CubeRoot(number) in a cell, where the number is the value at which you want to find the cube root. For example, =CubeRoot(125) will return 5.

To add this code in Excel, first open the Developer tab on the ribbon. You can enable it from Excel Options under the Customize Ribbon section if it’s not visible. Once the Developer tab is active, click the “Visual Basic” button to open the VBA editor. You can insert a new module and start typing your VBA code directly into the code window.

Last Updated: May 10, 2024