ISNUMBER
Is this really a number?
Ask whether a value is really a number
TRUE if the value is a number, FALSE for anything else
Syntax
=ISNUMBER(text)
| Argument | Required | What goes here |
|---|---|---|
text | Required | The cell to check, usually A2. |
How to use ISNUMBER
ISNUMBER answers the question a right-aligned column looks like it has already answered. A figure that arrived as text sits on the left of the cell and will not add up, and this is how you prove that is what happened.
It is the first thing to reach for when a total comes out lower than it should, or comes out as nought.
Its other use is as a companion to SEARCH: SEARCH errors when it finds nothing, so ISNUMBER around it turns "where is this word" into "is this word there at all".
Examples
Every result below is worked out by the same evaluator that marks your answers, on the sheet shown here.
| A | B | C | D | |
|---|---|---|---|---|
| 1 | Reference | Supplier name | Amount | Posted |
| 2 | GL-6100-8801 | brightwell paper | 1500 | Y |
| 3 | GL-6200-8802 | calder UTILITIES | 320 | y |
| 4 | GL-6100-8803 | meridian freight ltd | 2750 | |
| 5 | GL-6300-8804 | ashgrove catering | 184 | Y |
| 6 | GL-6200-8805 | THORNBURY print | 760 | |
| 7 | GL-6100-8806 | Brightwell Paper | 1120 | Y |
| Formula | Result |
|---|---|
=ISNUMBER(C2)The amount column arrived as text, so this is FALSE even though the cell reads 1500. | FALSE |
=ISNUMBER(VALUE(C2))VALUE converts it, and now it is a number. | TRUE |
=SUM(C2:C7)What the text column does to a total. Nothing is added, and nothing warns you. | 0 |
=ISNUMBER(SEARCH("freight",B4))The other use: SEARCH gives back a position when the word is there, and ISNUMBER turns that position into a plain yes. | TRUE |
Notes
- A cell can hold text that looks exactly like a number. Widening the column will not tell you which you have; this will.
- Dates on this site are held as text in the form 2026-10-31, so ISNUMBER is FALSE for a date.
Related
A reference tells you what it does. A unit makes you use it.