---
title: "491 in Roman numerals is CDXCI"
description: "491 in Roman numerals is CDXCI, written as 400 + 90 + 1. How it breaks down, how to write it, and the numbers either side."
url: https://atoneplace.net/roman-numerals/491/
site: "At One Place"
---

# 491 in Roman numerals

**491 in Roman numerals: CDXCI**

491 is written CDXCI in Roman numerals. That is 3 symbol groups added together, reading left to right from the largest value down.

## How it breaks down

*CDXCI = 400 + 90 + 1 = 491*

| Group | Value | Subtraction | Running total |
| --- | --- | --- | --- |
| CD | 400 | D − C | 400 |
| XC | 90 | C − X | 490 |
| I | 1 | — | 491 |

## Why the smaller symbol comes first

CDXCI uses subtractive notation in 2 places: CD means D minus C, or 400; XC means C minus X, or 90. 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 | yes — 1× |
| V | 5 | no |
| X | 10 | yes — 1× |
| L | 50 | no |
| C | 100 | yes — 2× |
| D | 500 | yes — 1× |
| M | 1,000 | no |

## The same number, other ways

- **In words:** Four hundred ninety-one
- **Roman numeral:** CDXCI
- **Symbol count:** 5 characters
- **Binary:** 111101011
- **Hexadecimal:** 1EB

## The numbers either side

| Number | Roman numeral |
| --- | --- |
| 489 | CDLXXXIX |
| 490 | CDXC |
| 491 | CDXCI ← |
| 492 | CDXCII |
| 493 | CDXCIII |

## Common questions

### What is 491 in Roman numerals?

491 is CDXCI.

### What does CDXCI mean?

CDXCI is the Roman numeral for 491 — 400 + 90 + 1.

### How do you write 491 in Roman numerals?

Take the largest value that fits and repeat until nothing is left: CD (400), then XC (90), then I (1). That gives CDXCI.

## Related pages

- [489 in Roman numerals](https://atoneplace.net/roman-numerals/489/)
- [490 in Roman numerals](https://atoneplace.net/roman-numerals/490/)
- [492 in Roman numerals](https://atoneplace.net/roman-numerals/492/)
- [493 in Roman numerals](https://atoneplace.net/roman-numerals/493/)
- [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/)