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How to Use the ISNUMBER Function in Google Sheets

There are many functions in Google Sheets that you can use to check whether a value or cell contents meet certain criteria.

One such function is the ISNUMBER function. Although at first, this might not seem like a very useful function, when you start to combine it with other functions it becomes very powerful.

In this tutorial, I will show you how to use the ISNUMBER function in Google Sheets, and show you ways that it can be used with other functions in your spreadsheet.

Table of Contents


The ISNUMBER function checks whether a value is a number. It will return TRUE if the value is a number, and FALSE if it is not.

The syntax of this function is:


  • Value – this is the value that will be checked to see if it is a number or not. You can put a value directly in the function or it can be a cell reference.

Here is an example of how this formula is used:

ISNUMBER example

You can see in the above image, the formula is very simple to use. The only argument used in the formula is the cell reference or value that you want to be checked. For the values that are numbers, it returns TRUE, and for the values that are not numbers, it will return FALSE.

Practical Uses of the ISNUMBER Function

As we covered earlier, the ISNUMBER function is usually used in combination with other functions depending on what you are trying to achieve in your spreadsheet.

Here we will go over some common ways this function is used with other functions to achieve certain results.

If Cell Contains Number

One of the most common ways the ISNUMBER function is used is in combination with the IF function. By nesting together these two functions you can create a formula that will check to see if a cell contains a number, and then if it is, you can return a designated value.

You will be nesting together the functions like this:

=IF(ISNUMBER(value),”value if true” , “value if false”)

  • Value – this is the value or cell to be checked whether it contains a number
  • Value if true – this is what will be returned if ISNUMBER returns TRUE
  • Value if false – this is what will be returned if ISNUMBER returns FALSE

Here is an example of how it can be used in our spreadsheet:


You can see with this formula, you get to specify the value that is returned if your checked value is a number.

Hopefully, now you can understand how this can be useful as you begin combining it with other functions.

Conditional Formatting with the ISNUMBER Function

Another common use of the ISNUMBER function is to apply conditional formatting to cells that contain numbers by creating a custom formula. With this, you can highlight cells that contain numbers.

Here is how this is done:

1. First, highlight the range of cells that you want to apply the conditional formatting to

ISNUMBER conditional format

2. Then in the top menu select Format, and then select Conditional formatting

ISNUMBER conditional format-1

3. A tab should now appear on the right-hand side of your screen. In this tab, find the Format rules section and set the “Format cells if” section to Custom formula is

ISNUMBER conditional format-2

4. In the text field below the Custom formula is a section, enter your formula. In this example, my formula is “=ISNUMBER(A2)”. Put the formula that corresponds to your range of cells in your data

ISNUMBER conditional format-3

5. Next select Fill color

ISNUMBER conditional format-4

6. Choose the color that your numbers will highlight to, and select Done when are finished

ISNUMBER conditional format-5

7. You should now see all of the numbers in the range you selected in step 1 are highlighted with the conditional formatting that you have chosen

ISNUMBER conditional format-6


Closing Thoughts

In this tutorial, I have shown you the basics of the ISNUMBER function and a couple of practical ways that it can be combined to do other things by combining with other functions and rules.

This is just scratching the surface of how you might use this function in your own spreadsheets. As you get more experience you will find many creative ways to use this in combination with other functions depending on what you are trying to accomplish.

More Google Sheets Tutorials:
If Cell Contains
How to Do Multiple IF Statements