---
title: "40 in Roman numerals is XL"
description: "40 in Roman numerals is XL, written as 40. How it breaks down, how to write it, and the numbers either side."
url: https://atoneplace.net/roman-numerals/40/
site: "At One Place"
---

# 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

*XL = 40 = 40*

| 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](https://atoneplace.net/roman-numerals/38/)
- [39 in Roman numerals](https://atoneplace.net/roman-numerals/39/)
- [41 in Roman numerals](https://atoneplace.net/roman-numerals/41/)
- [42 in Roman numerals](https://atoneplace.net/roman-numerals/42/)
- [4 in Roman numerals](https://atoneplace.net/roman-numerals/4/)
- [9 in Roman numerals](https://atoneplace.net/roman-numerals/9/)
- [14 in Roman numerals](https://atoneplace.net/roman-numerals/14/)
- [19 in Roman numerals](https://atoneplace.net/roman-numerals/19/)
- [49 in Roman numerals](https://atoneplace.net/roman-numerals/49/)
- [50 in Roman numerals](https://atoneplace.net/roman-numerals/50/)
- [64 in Roman numerals](https://atoneplace.net/roman-numerals/64/)
- [90 in Roman numerals](https://atoneplace.net/roman-numerals/90/)

## Sources

- Calculated on this page — At One Place (/about/)