EXPLICIT
Separate blank from zero
If C2 is the numerator and D2 is the denominator, return a blank when the denominator is missing and a readable label when it is truly zero.
Blank input, zero input, and valid division
=IF(D2="","",IF(D2=0,"Not applicable",C2/D2))Format the result cell as a percentage if the ratio represents a rate. Number formatting changes the display, not the calculation.
PAIR CHECK
Require both inputs when the metric needs both
Wait until numerator and denominator are present
=IF(OR(C2="",D2=""),"",IF(D2=0,"Not applicable",C2/D2))This avoids displaying zero only because the numerator has not arrived yet. Use it when an incomplete pair should remain visually empty.
DO NOT HIDE
Why broad IFERROR can be risky
=IFERROR(C2/D2,"") gives the same blank result for a zero denominator, a deleted reference, or an unexpected data type. Use IFERROR only when every error in the protected expression has the same defined business meaning.
SOURCE