Roman Numeral Converter

Convert between Roman numerals and Arabic numbers with a full symbol breakdown

Enter any whole number between 1 and 3,999

Roman Numeral

// Symbol Breakdown

// Step-by-Step

// Roman Numeral Symbols — Click to Convert

I
1
V
5
X
10
L
50
C
100
D
500
M
1,000

// Notable Years — Click to Convert

1066
Battle of Hastings
1492
Columbus sails
1776
US Independence
1969
Moon landing
2000
Millennium
2024
Last year
2025
This year
3999
Maximum value

// Conversion History

Your conversions will appear here

How Roman Numerals Work

Roman numerals use seven symbols combined using additive and subtractive notation. Symbols are generally written from largest to smallest (left to right), and their values are added together. When a smaller value appears before a larger one, it is subtracted — this is the subtractive rule.

The Subtractive Pairs

Where Roman Numerals Are Used Today

Roman numerals are still common on clock faces, book chapter numbering, film credits and sequels (Super Bowl LVIII), copyright years on films and television, and formal documents. They are also used in medical prescriptions and academic contexts.

Note: Standard Roman numeral notation supports integers from 1 to 3,999. The number 0 has no Roman numeral representation. Numbers above 3,999 require non-standard extensions not covered here.

// Memory Aid

I Very eXcited Lucy Counts Digits Most — I(1) V(5) X(10) L(50) C(100) D(500) M(1000).

// Max Repetition

The same symbol can appear at most 3 times in a row: III=3, but 4 is IV not IIII. V, L and D are never repeated.

// Clock Faces

Most clock faces use IIII instead of IV for 4. This is a historical quirk — it balances the VIII on the opposite side visually.

// Super Bowl

The Super Bowl uses Roman numerals — except Super Bowl 50, which used "50" instead of "L" because the NFL felt L looked awkward as a title.