Summary

ISODD returns TRUE when a number is odd and FALSE when it is not. Like ISEVEN, it is often used in formatting patterns, simple grouping rules, and cycle checks.

The decimal rule is the same here too. Excel truncates the decimal part before checking, so 11.9 is treated as 11.

Syntax

=ISODD(number)

You can use a number, a formula, or a cell reference.

Arguments

• number - [required] The value you want to test for odd parity.

ISODD vs Other Functions

Using ISODD

This function is useful when odd values need special treatment. It works well in alternating layouts, audit sampling, and simple A/B style logic where odd-numbered items go one way and even-numbered items go another.

It is also worth remembering that zero returns FALSE here because zero is even, not odd.

Example 1 - Check odd row numbers

This is a simple layout pattern.

=ISODD(ROW())

Example 2 - See the truncation rule

Decimals are truncated before parity is checked.

=ISODD(11.9) // Returns TRUE because Excel checks 11.

Example 3 - Check a negative odd value

Negative odd integers still return TRUE.

=ISODD(-3) // Returns TRUE.

Example 4 - Use it for a split rule

This keeps an odd-even split readable.

=IF(ISODD(B1),"Audit Required","Standard Path")

Conclusion Recap

• Main job: ISODD checks whether a number is odd.
• Decimal rule: Excel truncates before checking.
• Zero: It returns FALSE because zero is even.
• Good uses: Layout logic, sampling rules, and grouping patterns.