The Excel ISNUMBER function is an Information formula that returns TRUE if value is a number, and FALSE if not. As the name suggests, the formula asks the question "Is number?" to its argument. This way, you can test the outcome of a formula or a cell value using this function. This formula can be especially useful in analyzing a large data set. In this guide, we’re going to show you how to use the Excel ISNUMBER function and also go over some tips and error handling methods.

Supported versions

  • All Excel versions

Excel ISNUMBER Function Syntax



valueThe value you want to test.


The ISNUMBER function, just like the other IS… functions, only requires a single argument. A common use case for this function is testing a value of cell or value that is returned by a formula. The function returns TRUE for numeric outcomes, and FALSE otherwise. Please note that date serial values are also considered as numbers by Excel.

=ISNUMBER(4) returns TRUE

=ISNUMBER(DATE(2020,8,25)) returns TRUE

=ISNUMBER("text") returns FALSE

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  • You can use the Excel ISNUMBER function as part of the logical test of an IF function.
    =IF(ISNUMBER(A1),"Logical","Not logical")
  • Excel keeps date and time values as numbers. Excel assumes that Jan 1st, 1900 is 1, and every subsequent date value is based on this. While whole numbers represent days, decimals represent time values. For example; 1/1/2018 is equal to 43101, and 12:00 is equal to 5. Because of this, the Excel ISNUMBER function counts date time values as numbers.
  • IFERROR function can return a specific value if an error occurs.
  • Below is a list of other IS… functions: