What number range is supported?

Convert standard integers from 1 to 3,999 (I to MMMCMXCIX) bidirectionally.

Can I convert Roman numerals back to numbers?

Yes, type any valid Roman numeral (e.g. `MMXXVI`) to see its decimal integer equivalent (`2026`).

How does it handle invalid Roman numeral inputs?

Invalid syntax patterns (like 'IIII' or 'VX') are flagged immediately with helpful hints.

Free Roman Numeral Converter

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Roman Numeral Converter (Bi-Directional)

Convert Arabic numbers (1-3999) to Roman Numerals or translate Roman Numerals back to numbers instantly.

Number → Roman Numeral

Enter an Integer (1 - 3999):

MCMXCIV

Roman Numeral → Number

Enter Roman Numeral:

2026

Roman Numeral Cheat Sheet

I 1

V 5

X 10

L 50

C 100

D 500

M 1000

IV 4

IX 9

XL 40

XC 90

CD 400

CM 900

How Roman Numerals Work

Roman numerals originated in ancient Rome and use combinations of letters from the Latin alphabet (I, V, X, L, C, D, M) to represent values. Subtractives are used when a smaller value appears before a larger one (such as IV for 4 or IX for 9).

Frequently Asked Questions

What is the maximum number supported?
Standard Roman numeral notation without overline bars supports numbers up to 3,999 (MMMCMXCIX).

Is zero represented in Roman numerals?
The ancient Romans did not have a dedicated symbol for zero (0), though the Latin word nulla was occasionally used.