ISERR function
ISERR returns TRUE for any error except #N/A. That makes it the right test when "not found" is an expected, meaningful result, but a #DIV/0! or #VALUE! means the data is bad and should be flagged.
- Available in
- Every current version
- Category
- Information functions
- Returns
- TRUE for every error except #N/A, such as #VALUE!, #REF! or #DIV/0!. FALSE for #N/A and for every value that isn't an error.
- Google Sheets
- Available in Google Sheets with the same argument.
Syntax
=ISERR(value)
| Argument | Required? | What it is |
|---|---|---|
value | Required | The value, cell or formula to test. |
Examples
Each result below is calculated from the sample sheet by our formula engine, the same one that grades the practice.
| Cell | Formula | Result | What it shows |
|---|---|---|---|
| E2 | =ISERR(MATCH("Gizmo",A2:A5,0)) | FALSE | FALSE: a missing product is #N/A, which ISERR ignores |
| F2 | =ISERR(B2/C2) | TRUE | TRUE: zero units gives #DIV/0! |
| G2 | =IF(ISERR(B4/C4),"Bad data",B4/C4) | Bad data | Text in the units column is flagged |
Try it live
This is the sample sheet. Change any number or text, or edit a formula, and the results update.
Show the sample data as a table
| Product | Revenue | Units | Gizmo lookup | Lamp per unit | Hub data check | |
| Desk lamp | 1872 | 0 | FALSE | TRUE | Bad data | |
| Monitor arm | 1958 | 22 | ||||
| USB hub | 1769 | n/a | ||||
| Webcam | 1173 | 17 |
Practice ISERR
Graded instantly, then re-checked on changed data.
Cost per attendee
D2, use ISERR to return the cost per attendee (B2 divided by C2), or the text Check if the division fails. Fill down to D7.Common mistakes
| What you see | Why, and how to fix it |
|---|---|
| A missing item isn't flagged | ISERR is FALSE for #N/A on purpose. Use ISERROR or ISNA if a failed lookup should be caught. |
| The calculation runs twice | IF(ISERR(x),"",x) calculates x twice. In a long formula, =LET(v,x,IF(ISERR(v),"",v)) calculates it once. |
Tips
- Pair it with ISNA for a three-way result: found, not found, or bad data.
Questions
What does ISERR do in Excel?
It returns TRUE when a value is an error other than #N/A, such as #DIV/0! or #VALUE!.
When should I use ISERR instead of ISERROR?
When #N/A is an expected answer, such as an item that isn't in a lookup table, but any other error means the data is broken.
Last reviewed October 2026. Every example result on this page is calculated live by the Spreadsheet Practice formula engine.