40 in Words
How do you write 40 in words?
The number 40 is written forty in words. As an ordinal it is fortieth, and on a check you would write Forty and 00/100.
Last updated 24 August 2026
Other ways to write it
| Cardinal | forty |
|---|---|
| Ordinal | fortieth |
| Currency | forty dollars |
| Check format | Forty and 00/100 |
How 40 is written
40 occupies one place value, 40 in the tens place, and is written forty.
Its ordinal form is fortieth — only the final element takes the ordinal ending — and on a check the amount line reads "Forty and 00/100", where 00/100 stands for zero cents.
Its Roman numeral XL uses subtractive notation: XL means 40, written as X before L instead of repeating X.
For house-style rules on spelling out numbers, see the Chicago Manual of Style.
Facts about 40
- 40 is an even number.
- It is not a prime number.
- Digit sum: 4.
- Roman numerals: XL.
- Binary: 101000.
- Hexadecimal: 28.
| Digit | Place |
|---|---|
| 4 | tens |
| 0 | ones |
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Frequently asked questions
How do you write 40 in words?
40 in words is "forty".
How do you spell 40?
40 is spelled "forty".
How do you write 40 on a check?
On a check, write "Forty and 00/100".