40 in Roman numerals
40 in Roman numerals
XL
40 is written XL in Roman numerals. That is 1 symbol group added together, reading left to right from the largest value down.
How it breaks down
| Group | Value | Subtraction | Running total |
|---|---|---|---|
| XL | 40 | L − X | 40 |
Why the smaller symbol comes first
XL uses subtractive notation in one place: XL means L minus X, or 40. A smaller symbol placed before a larger one is subtracted from it rather than added, which is why IX is nine and not eleven.
Only six such pairs are valid — IV, IX, XL, XC, CD and CM. That restriction is what makes the notation unambiguous: IIII and IC both look like they should work, but neither is standard, and only one spelling of any number is correct.
The symbols
| Symbol | Value | Used here |
|---|---|---|
| I | 1 | no |
| V | 5 | no |
| X | 10 | yes — 1× |
| L | 50 | yes — 1× |
| C | 100 | no |
| D | 500 | no |
| M | 1,000 | no |
The same number, other ways
- In words
- Forty
- Roman numeral
- XL
- Symbol count
- 2 characters
- Binary
- 101000
- Hexadecimal
- 28
The numbers either side
| Number | Roman numeral |
|---|---|
| 38 | XXXVIII |
| 39 | XXXIX |
| 40 | XL ← |
| 41 | XLI |
| 42 | XLII |
Common questions
- What is 40 in Roman numerals?
- 40 is XL.
- What does XL mean?
- XL is the Roman numeral for 40 — 40.
- How do you write 40 in Roman numerals?
- Take the largest value that fits and repeat until nothing is left: XL (40). That gives XL.
Related pages
- 38 in Roman numerals XXXVIII
- 39 in Roman numerals XXXIX
- 41 in Roman numerals XLI
- 42 in Roman numerals XLII
- 4 in Roman numerals IV
- 9 in Roman numerals IX
- 14 in Roman numerals XIV
- 19 in Roman numerals XIX
- 49 in Roman numerals XLIX
- 50 in Roman numerals L
- 64 in Roman numerals LXIV
- 90 in Roman numerals XC
Sources
- Calculated on this page — At One Place