Part of the free Module 5: Excel Formulas and Functions · Function 64 of 105 · Full Excel course
The Excel NOT function reverses a logical value: it returns FALSE when its argument is TRUE and TRUE when its argument is FALSE. NOT in Excel is used to express “is not” conditions clearly, such as NOT(ISBLANK(A2)) for a filled cell or NOT(ISNUMBER(B2)) for anything that is not a number.
NOT syntax
=NOT(logical)Arguments
| Argument | Required | Meaning |
|---|---|---|
| logical | Required | A value or expression that evaluates to TRUE or FALSE. Numbers are accepted: 0 is treated as FALSE, any other number as TRUE. |
NOT takes exactly one argument. Text that cannot be interpreted as logical, such as “Yes”, produces #VALUE!.
Step-by-step example
Check that the value in B2 is not 100:
=NOT(B2=100)- Excel evaluates B2=100. With 100 in B2 that is TRUE.
- NOT flips TRUE to FALSE.
- The formula returns FALSE, meaning “it is not true that B2 differs from 100”. For any other value, the result is TRUE.
The same test can be written as =B2<>100. NOT earns its place when the inner expression has no “not equal” operator, as in the examples below.
Practical use cases
1. Cell is not blank
=IF(NOT(ISBLANK(A2)), "Entered", "Missing")2. Value is not a number
=IF(NOT(ISNUMBER(B2)), "Check input", B2*1.18)3. Value is not in a list
=IF(NOT(ISNUMBER(MATCH(A2, $F$2:$F$20, 0))), "Not approved", "Approved")4. Exclude weekends in conditional formatting
=NOT(OR(WEEKDAY($A2)=1, WEEKDAY($A2)=7))5. Text does not contain a word
=NOT(ISNUMBER(SEARCH("urgent", A2)))6. Toggle a flag cell
=NOT(C1)If C1 holds TRUE (a checkbox or earlier test), this returns FALSE, and vice versa.
7. Numeric coercion
=NOT(0) -- TRUE
=NOT(7) -- FALSECommon mistakes and errors
- #VALUE! – the argument is text that is not a logical value, e.g. NOT(“Yes”). Compare instead: NOT(A2=”Yes”).
- Too many arguments – NOT accepts one argument only. To negate several conditions, wrap them in AND or OR first: NOT(AND(A2>0, B2>0)).
- Double negatives – NOT(NOT(x)) is just x. Simplify for readability.
- Using NOT where <> is clearer – NOT(A2=5) and A2<>5 are identical; prefer the operator for simple comparisons.
- Array behaviour – NOT works element by element inside SUMPRODUCT and FILTER, so NOT(A2:A100=””) is fine; the limitation belongs to AND and OR, not NOT.
Tips and best practices
- Read the formula aloud. If “not is blank” is clearer than “is not equal to empty”, use NOT; otherwise use the <> operator.
- Combine NOT with ISNUMBER(SEARCH()) for “does not contain” tests in filters and conditional formatting.
- Avoid double negatives such as NOT(A2<>5); write A2=5.
- Use NOT in data validation to block specific values: =NOT(ISNUMBER(MATCH(A2, Blacklist, 0))).
- NOT works element-wise in arrays, so NOT(ISBLANK(A2:A100)) is a valid FILTER include argument in Excel 365.
Related functions
- AND and OR – combine conditions that NOT can then reverse.
- IF – acts on the TRUE/FALSE result.
- ISBLANK, ISNUMBER and ISTEXT – the tests most often wrapped in NOT.
- Browse the Excel Formulas hub or watch videos on YouTube.com/@PKAnExcelExpert.
Frequently asked questions
Can NOT reverse a number or a text string?
Numbers are accepted: NOT(0) is TRUE and NOT of any other number is FALSE. Plain text such as “Yes” returns #VALUE!; compare it to something first, for example NOT(A2=”Yes”).
Can NOT take more than one argument?
No. It accepts exactly one logical value. To negate several tests, combine them with AND or OR inside NOT.
When should I use NOT instead of the <> operator?
Use <> for simple “not equal” checks. Use NOT when reversing a function that has no opposite, such as NOT(ISBLANK(A2)), NOT(ISNUMBER(B2)) or NOT(ISNUMBER(SEARCH(…))).
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