These functions are useful for detecting errors in Excel formulas.

Common Excel Errors

Error	Meaning
#DIV/0!	Division by zero
#VALUE!	Incorrect data type
#REF!	Invalid cell reference
#NAME?	Unrecognized name/function
#N/A	Value not available
#NUM!	Invalid numeric value

ISERROR

Checks whether a value contains any Excel error.

Syntax

=ISERROR(value)

Example:

=ISERROR(A2/B2)

If B2 contains 0, the formula returns:

TRUE

ISERR

Checks for errors except #N/A.

=ISERR(value)

ISNA

Checks specifically for #N/A.

=ISNA(value)

Practical Example

Instead of showing an error:

=IF(ISERROR(A2/B2),”Invalid Calculation”,A2/B2)

Result:

Invalid Calculation

Practice

Create a worksheet containing intentional Excel errors and use:

• ISERROR
• ISERR
• ISNA

to identify them.