How to use the Excel ISNA function

Summary

The Excel ISNA function returns TRUE when a cell contains the #N/A error and FALSE for any other value, or any other error type. You can use the ISNA function with the IF function test for an error and display a friendly message when it appears.

Purpose

Test for the #N/A error

Return value

A logical value (TRUE or FALSE)

Syntax

=ISNA (value)

Arguments

value - The value to check if #N/A.

Usage notes

Use the ISNA function to check to check for #N/A errors. Normally, value is supplied as a cell reference. For example, if A1 contains #N/A, the following formula will return TRUE:

=ISNA(A1)

To explicitly force the #N/A error in a formula, you can use the NA function. The following will return true:

=ISNA(NA())

Notes:

ISNA is part of a group of functions called the "IS functions", which are often used to test the result of formulas for errors.
With Excel 2007+, the IFERROR function can provide simpler, less redundant error checking.
With Excel 2013+, the IFNA function can trap and handle #N/A errors specifically.

Related functions

Excel ISERROR Function

The Excel ISERROR function returns TRUE for any error type excel generates, including #N/A, #VALUE!, #REF!, #DIV/0!, #NUM!, #NAME?, or #NULL! You can use ISERROR together with the IF function to test for errors and display a custom message, or...

Excel IFERROR Function

The Excel IFERROR function returns a custom result when a formula generates an error, and a standard result when no error is detected. IFERROR is an elegant way to trap and manage errors without using more complicated nested IF statements.

Excel ISBLANK Function

The Excel ISBLANK function returns TRUE when a cell contains is empty, and FALSE when a cell is not empty. For example, if A1 contains "apple", ISBLANK(A1) returns FALSE.

Excel ISERR Function

The Excel ISERR function returns TRUE for any error type except the #N/A error. You can use the ISERR function together with the IF function to test for an error and display a custom message, or perform a different calculation if found.

Excel ISEVEN Function

The Excel ISEVEN function returns TRUE when a numeric value is even, and FALSE for odd numbers. ISEVEN will return the #VALUE error when a value is not numeric.

Excel ISFORMULA Function

The Excel ISFORMULA function returns TRUE when a cell contains a formula, and FALSE if not. When a cell contains a formula ISFORMULA will return TRUE regardless of the formula's output or error conditions.

Excel ISLOGICAL Function

The Excel ISLOGICAL function returns TRUE when a cell contains the logical values TRUE or FALSE, and returns FALSE for cells that contain any other value, including empty cells.

Excel ISNONTEXT Function

The Excel ISNONTEXT function returns TRUE for any non-text value, for example, a number, a date, a time, etc. The ISNONTEXT function also returns TRUE for blank cells, and for cells with formulas that return non-text results.

Excel ISNUMBER Function

The Excel ISNUMBER function returns TRUE when a cell contains a number, and FALSE if not. You can use ISNUMBER to check that a cell contains a numeric value, or that the result of another function is a number.

Excel ISODD Function

The Excel ISODD function returns TRUE when a numeric value is odd, and FALSE for even numbers. ISODD will return the #VALUE error when a value is not numeric.

Excel ISREF Function

The Excel ISREF returns TRUE when a cell contains a reference and FALSE if not. You can use the ISREF function to check if a cell contains a valid reference.

Excel ISTEXT Function

The Excel ISTEXT function returns TRUE when a cell contains a text, and FALSE if not. You can use the ISTEXT function to check if a cell contains a text value, or a numeric value entered as text.

Good links

Microsoft ISNA function documentation

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