a formula divides by zero or by an empty cell.

what it means

division by zero is undefined, so the formula cannot produce a number. An empty cell counts as zero, which is why this error often appears before any data is entered.

a formula that produces it

=1/0

common causes

• an explicit division by zero, e.g. =1/0
• the divisor cell is empty or holds 0
• AVERAGE over a range with no numeric values
• a percentage or ratio computed before its denominator is filled in

how to fix it

• guard the division: =IF(B1=0, "", A1/B1)
• use IFERROR to show a fallback: =IFERROR(A1/B1, "")
• check that the denominator range actually contains numbers

related

#NUM! · #VALUE!