Information
ISODD Function in Excel
Returns TRUE if the number is odd.
Syntax
- =ISODD(number)
Arguments
- number (required): Number to test
Examples
- =ISODD(5) - Test if 5 is odd - Result: TRUE
- =ISODD(4) - Test if 4 is odd - Result: FALSE
Defensive formulas with ISODD
- Use IS* functions inside IF to branch on blank, error, text, or number cells.
- Prefer [IFERROR](/functions/iferror/) when you only need a fallback display value.
- Error hub: [Fix formula errors](/guides/fix-excel-formula-errors/).
Common errors
- #VALUE! if not a number
- Truncates decimals before testing
Use cases
- Conditional formatting
- Alternating rows
- Data validation
Frequently asked questions
- What is ISODD used for in Excel? ISODD tests if a number is odd (not divisible by 2), returning TRUE or FALSE. It's commonly used for alternating row formatting, data validation, and creating conditional logic based on number parity.
- How can I use ISODD with MOD for the same result? ISODD(5) is equivalent to MOD(5,2)=1. Both return TRUE for odd numbers. MOD is more flexible for other divisibility tests (like MOD(n,3)=0 for multiples of 3), while ISODD is clearer for odd/even checks.
- Does ISODD work with negative numbers? Yes, ISODD works with negative numbers. ISODD(-3) returns TRUE, ISODD(-4) returns FALSE. The function tests the absolute mathematical property of being odd, regardless of sign.
Editorial review
- Reviewed by Excel.Directory Editorial Team. Updated May 2026.