To act on whether a cell is empty — show “missing,” hold a calculation until data arrives — use ISBLANK inside IF. One subtlety trips everyone: a formula returning "" is not blank to ISBLANK.
The example
Flag the rows with a missing value.
| A | B | |
|---|---|---|
| 1 | Value | Status |
| 2 | 42 | OK |
| 3 | Missing | |
| 4 | 17 | OK |
The formula
The status in B2:
How it works
ISBLANK is a strict empty test:
ISBLANK(A2)returns TRUE only when A2 holds nothing at all — no value, no formula.- IF then returns “Missing” for empty cells and “OK” otherwise.
- A cell with a formula that outputs
""is not blank to ISBLANK — it contains a formula. Use=A2=""if you want to treat""as empty too.
Hold a calculation until a cell is filled: =IF(A2="", "", A2*B2) shows nothing until both inputs exist — cleaner than a sheet full of zeros or errors.
Try it: interactive demo
Type a value or clear it; see the status.
Variations
Treat "" as blank too
Catches empty-string formula results:
Count the blanks
COUNTBLANK for a whole range:
Do the calc only when filled
Avoid premature errors:
Pitfalls & errors
ISBLANK vs ="". ISBLANK is FALSE for a formula that returns "" (the cell isn’t empty, it has a formula). Use =A2="" to treat both as blank.
A space isn’t blank. A cell with one space is not empty. Clean with TRIM if stray spaces are sneaking in.
Merged cells confuse ISBLANK. Only the top-left cell of a merge holds the value; the others read as blank.
Practice workbook
Frequently asked questions
How do I check if a cell is blank in Excel?
Why does ISBLANK say a cell isn't blank when it looks empty?
How do I stop a formula calculating until a cell is filled?
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