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ISBLANK

Checks whether a cell is blank and returns TRUE or FALSE.

Quick Example​

=ISBLANK(A1)

Returns TRUE if A1 is blank, FALSE otherwise.

Syntax​

=ISBLANK(value)

Arguments​

  • value (required): The cell reference to check

Examples​

=ISBLANK(A1)                         // TRUE if A1 is empty
=ISBLANK("")                         // FALSE (empty string is not blank)
=IF(ISBLANK(A1), "Required", "OK")   // Validation
=COUNTIF(A1:A10, ISBLANK(A1:A10))    // Count blank cells

What Counts as Blank​

Returns TRUE For​

  • Completely empty cells (never had content)
  • Cells cleared of content

Returns FALSE For​

  • Empty strings: ""
  • Spaces: " "
  • Zero: 0
  • Text: any text value
  • Numbers: any numeric value
  • Formulas that return ""
  • Errors: #DIV/0!, #VALUE!

How It Works​

Empty String vs Blank​

=ISBLANK("")      // FALSE (empty string exists)
=ISBLANK(A1)      // TRUE if A1 truly blank

If A1 contains ="", ISBLANK(A1) returns FALSE because the cell contains a formula result.

Error Handling​

Returns FALSE for errors (does not propagate them):

=ISBLANK(#DIV/0!)  // FALSE

Common Use Cases​

  • Required field validation: =IF(ISBLANK(A1), "Required", "")
  • Conditional calculations: =IF(ISBLANK(B1), 0, A1*B1)
  • Count filled cells: =ROWS(A1:A10) - COUNTIF(A1:A10, ISBLANK(A1:A10))
  • Data completeness: =IF(ISBLANK(A1), "Incomplete", "Complete")

Using with Ranges​

=ISBLANK(A1:A5)

For a range, returns TRUE only if ALL cells are blank.

Comparison: ISBLANK vs LEN vs ""​

Check for Blank​

=ISBLANK(A1)           // TRUE only if truly empty

Check for Empty (including "")​

=A1 = ""               // TRUE for blank or empty string
=LEN(A1) = 0           // TRUE for blank or empty string