Cleanup function
Excel ISNUMBER function
ISNUMBER returns TRUE if a value is a number and FALSE for anything else. Use it to catch numbers stored as text, guard a calculation, or turn SEARCH into a simple "does this cell contain" test.
=ISNUMBER(value)Arguments
value- The cell or value to test.
ISNUMBER examples
Every result below was calculated from this sample sheet by the same spreadsheet engine the Cellwise app uses.
| A | B | C | D | |
|---|---|---|---|---|
| 1 | SKU | Product | In stock | Reorder at |
| 2 | CB-100 | USB-C cable | 42 | 20 |
| 3 | CB-101 | HDMI cable | 15 | 10 |
| 4 | AD-200 | Wall adapter | TBC | 15 |
| 5 | AD-201 | Car adapter | 8 | 12 |
Result: TRUE
TRUE, because 42 is a real number.
Result: FALSE
FALSE. The 15 was imported as text, so totals will skip it.
Result: Reorder
Only compares stock levels when the count is a real number.
Result: TRUE
TRUE when the product name contains "cable" anywhere.
How to use ISNUMBER
- Click the cell for the result.
- Type =ISNUMBER( and click the cell to test.
- Press Enter to see TRUE or FALSE.
- Wrap it in IF or use it in conditional formatting.
Common ISNUMBER mistakes
Numbers stored as text
They look like numbers but ISNUMBER says FALSE. Convert them with VALUE or Text to Columns.
Forgetting that dates are numbers
A real date returns TRUE, because Excel stores dates as serial numbers.
Using FIND or SEARCH alone to test for text
They return #VALUE! when nothing is found. Wrap them in ISNUMBER for a clean TRUE or FALSE.
ISNUMBER FAQ
How do I check if a cell contains specific text in Excel?
Use =ISNUMBER(SEARCH("text",A2)). SEARCH returns a position number when it finds the text, so ISNUMBER turns that into TRUE.
Why does ISNUMBER return FALSE for a number?
The number is stored as text, often from an import. Look for a green triangle in the cell corner and convert it to a number.
Does ISNUMBER return TRUE for dates?
Yes. Excel dates are numbers underneath, so a real date gives TRUE. A date typed as text gives FALSE.
Practice ISNUMBER in these lessons
Guides that use ISNUMBER
- How to compare two columns in Excel
- If a cell contains text, return a value in Excel
- #VALUE! error in Excel: causes and fixes
Related functions
Updated