Information

ISNUMBER Function in Excel

Returns TRUE if the value is a number.

Syntax

  • =ISNUMBER(value)

Arguments

  • value (required): The value to check

Examples

  • =ISNUMBER(123) - Check number - Result: TRUE
  • =ISNUMBER("123") - Check text number - Result: FALSE

Defensive formulas with ISNUMBER

  • 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

  • Numbers stored as text return FALSE

Use cases

  • Data validation
  • Type checking
  • Conditional logic

Frequently asked questions

  • How do I check if a cell contains a number stored as text? Numbers as text show FALSE for ISNUMBER but TRUE for ISTEXT. To detect: =AND(ISTEXT(A1), ISNUMBER(VALUE(A1))) returns TRUE for text that can be converted to number. Or check for green triangle indicator in cells.
  • How do I use ISNUMBER with SEARCH for partial matches? =ISNUMBER(SEARCH("keyword", A1)) returns TRUE if A1 contains "keyword". SEARCH returns a number (position) if found, or #VALUE! if not. ISNUMBER converts this to TRUE/FALSE for easy filtering.

Editorial review

  • Reviewed by Excel.Directory Editorial Team. Updated May 2026.

When to use ISNUMBER

  • Data validation — common Information scenario for ISNUMBER.
  • Type checking — common Information scenario for ISNUMBER.
  • Conditional logic — common Information scenario for ISNUMBER.

ISNUMBER in the Information category

  • Browse all Information functions at /categories/information/ for related formulas.
  • ISNUMBER syntax: =ISNUMBER(value)
  • value (required): The value to check
  • Confirm ISNUMBER arguments match the syntax shown above before filling down.
  • Lock table and range references with $ when copying formulas across rows or sheets.

Formula checklist before you copy down

  • Confirm ISNUMBER arguments match the syntax shown above before filling down.
  • Lock table and range references with $ when copying formulas across rows or sheets.
  • If results look wrong, check for text stored as numbers and invisible spaces with TRIM.
  • Spot-check three known input rows manually against expected output.

Related Excel functions

  • ISTEXT (/functions/istext/): Returns TRUE if the value is text.
  • ISBLANK (/functions/isblank/): Returns TRUE if the cell is empty.
  • VALUE (/functions/value/): Converts a text string that represents a number to a number.

Errors to watch for

  • Numbers stored as text return FALSE — review causes on linked error pages in the directory.

Copy-paste audit workflow

  • Enter ISNUMBER on three test rows with known expected output documented on a QA tab.
  • Fill down only after absolute references are locked on lookup tables and rate tables.
  • Compare against manual calculation or a calculator for financial and statistical functions.
  • Search this directory for comparison guides when choosing between similar functions in the same category.

ISNUMBER worked examples to copy

  • =ISNUMBER(123) — Check number. Expected result: TRUE.
  • =ISNUMBER("123") — Check text number. Expected result: FALSE.

ISNUMBER reference summary for crawlers and offline review

  • ISNUMBER belongs to the Information category in Excel. Returns TRUE if the value is a number.
  • Full syntax: =ISNUMBER(value). Open /functions/isnumber/ for parameters, FAQs, and related pages.
  • Common mistakes: Numbers stored as text return FALSE
  • Pair this function with comparison guides when another Excel formula might fit the same task better.
  • Review fix-excel-formula-errors when unexpected errors appear after upgrading Excel or sharing across locales.