Roman Numeral Converter

Roman Numeral Converter — Free Roman numeral converter. Convert any number from 1 to 3999 to Roman numerals, or decode Roman numerals back to Arabic numbers. Works both ways — just type and get the answer instantly. No signup required.

→ RomanMode

—Input

—Valid

Number (1–3999)

Roman numeral

Number (1–3999)

Try an example

Roman numeral

Result appears here…

Roman numeral basics

Roman numerals use seven letters to represent numbers. They were the standard numbering system in ancient Rome and remained in use across Europe through the Middle Ages. Today they appear on clock faces, movie titles, chapter headings, and the Super Bowl.

Symbol	Value
I	1
V	5
X	10
L	50
C	100
D	500
M	1000

Subtractive notation — the key rule

When a smaller numeral appears before a larger one, it is subtracted. This keeps numerals shorter than pure additive notation would allow.

Roman	Meaning	Value
IV	5 − 1	4
IX	10 − 1	9
XL	50 − 10	40
XC	100 − 10	90
CD	500 − 100	400
CM	1000 − 100	900

Common years in Roman numerals

Year	Roman numeral
1776	MDCCLXXVI
1900	MCM
1999	MCMXCIX
2000	MM
2001	MMI
2024	MMXXIV
2025	MMXXV
3999	MMMCMXCIX

Why Roman numerals stop at 3999

The largest symbol in standard Roman numerals is M (1000). Three Ms in a row give you MMM = 3000, and the remaining 999 can be expressed as CMXCIX. Beyond 3999, you'd need four Ms (MMMM) which is non-standard. Historical manuscripts used a bar over a numeral to multiply it by 1000 — so V̄ = 5,000 — but this is not supported in modern typesetting and this tool follows the standard 1–3999 range.

Frequently Asked Questions

What is the range of Roman numerals?

Standard Roman numerals cover 1 (I) to 3999 (MMMCMXCIX). There is no symbol for zero in the Roman system, and numbers above 3999 require non-standard extensions. This tool supports the standard 1–3999 range.

How do I convert a number to Roman numerals?

Select "Number → Roman", type your number (1–3999), and the Roman numeral appears instantly. For example: 2024 → MMXXIV, 42 → XLII, 1999 → MCMXCIX.

How do I read Roman numerals?

Roman numerals use letters: I (1), V (5), X (10), L (50), C (100), D (500), M (1000). When a smaller numeral appears before a larger one, it is subtracted — for example, IV = 4 (5 − 1) and XC = 90 (100 − 10). Otherwise values are added left to right.

What year is MMXXIV?

MMXXIV is 2024. MM = 2000, XX = 20, IV = 4. This tool converts it back to 2024 instantly if you select "Roman → Number" mode.

Why do clocks use IIII instead of IV?

Many clock faces use IIII for 4 rather than the standard IV. This is a historical tradition — some say it balances the visual weight of the clock face (VIII on the right vs IIII on the left). It is technically incorrect by Roman numeral rules but widely accepted on clocks.