---
title: "31 in Roman numerals is XXXI"
description: "31 in Roman numerals is XXXI, written as 10 + 10 + 10 + 1. How it breaks down, how to write it, and the numbers either side."
url: https://atoneplace.net/roman-numerals/31/
site: "At One Place"
---

# 31 in Roman numerals

**31 in Roman numerals: XXXI**

31 is written XXXI in Roman numerals. That is 4 symbol groups added together, reading left to right from the largest value down.

## How it breaks down

*XXXI = 10 + 10 + 10 + 1 = 31*

| Group | Value | Subtraction | Running total |
| --- | --- | --- | --- |
| X | 10 | — | 10 |
| X | 10 | — | 20 |
| X | 10 | — | 30 |
| I | 1 | — | 31 |

## No subtraction needed

XXXI is purely additive — every symbol is simply added to the one before it, with no subtractive pairs like IV or IX. Numbers avoid subtraction when none of their digits is a 4 or a 9.

## The symbols

| Symbol | Value | Used here |
| --- | --- | --- |
| I | 1 | yes — 1× |
| V | 5 | no |
| X | 10 | yes — 3× |
| L | 50 | no |
| C | 100 | no |
| D | 500 | no |
| M | 1,000 | no |

## The same number, other ways

- **In words:** Thirty-one
- **Roman numeral:** XXXI
- **Symbol count:** 4 characters
- **Binary:** 11111
- **Hexadecimal:** 1F

## The numbers either side

| Number | Roman numeral |
| --- | --- |
| 29 | XXIX |
| 30 | XXX |
| 31 | XXXI ← |
| 32 | XXXII |
| 33 | XXXIII |

## Common questions

### What is 31 in Roman numerals?

31 is XXXI.

### What does XXXI mean?

XXXI is the Roman numeral for 31 — 10 + 10 + 10 + 1.

### How do you write 31 in Roman numerals?

Take the largest value that fits and repeat until nothing is left: X (10), then X (10), then X (10), then I (1). That gives XXXI.

## Related pages

- [29 in Roman numerals](https://atoneplace.net/roman-numerals/29/)
- [30 in Roman numerals](https://atoneplace.net/roman-numerals/30/)
- [32 in Roman numerals](https://atoneplace.net/roman-numerals/32/)
- [33 in Roman numerals](https://atoneplace.net/roman-numerals/33/)
- [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/)
- [40 in Roman numerals](https://atoneplace.net/roman-numerals/40/)
- [42 in Roman numerals](https://atoneplace.net/roman-numerals/42/)
- [49 in Roman numerals](https://atoneplace.net/roman-numerals/49/)
- [50 in Roman numerals](https://atoneplace.net/roman-numerals/50/)

## Sources

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