The ISBLANK function is an information function which will return either TRUE or FALSE if the selected cell or values result in a reference to a blank cell. It is important to understand that a cell containing a formula which evaluates to a blank value is not considered ‘blank’ as it contains a formula.

This is the format of the ISBLANK function:

=ISBLANK(REFERENCE OR FORMULA)

Here is an example of the ISBLANK function:

=ISBLANK(C3) = TRUE

This function is valuable when configuring a formula which requires different calculations based on which parameters are included or excluded by a user.

An example of a functional implementation of this would be performing a simple loan repayment schedule versus one with additional deposits towards the principle amount every period. If the user does not plan on making additional repayments the formula required is different from the one which includes additional repayment.

=IF(ISBLANK(C4),FORMULA WITHOUT REPAYMENT, FORMULA WITH REPAYMENT)