Roman Numeral Converter

Convert between Arabic numbers and Roman numerals with validation and analysis

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Conversion Mode

Convert Number to Roman Numeral

Numbers from 1 to 3999
Enter a value to see conversion

Common Examples

Current Year

2024 → MMXXIV

Super Bowl

XLIX → 49

Movie Sequel

4 → IV

21st Century

XXI → 21

Book Title

1984 → MCMLXXXIV

Clock Number

XII → 12

Roman Numeral Reference

Basic Symbols

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

Conversion Rules

Addition Rule

When a smaller numeral appears after a larger one, add the values.
Example: VI = V + I = 5 + 1 = 6

Subtraction Rule

When a smaller numeral appears before a larger one, subtract the smaller.
Example: IV = V - I = 5 - 1 = 4

Repetition Rule

I, X, C, and M can be repeated up to 3 times. V, L, and D cannot be repeated.
Example: III = 3, but not IIII

Order Rule

Numerals are written from largest to smallest, left to right.
Example: MCMLXXXIV (1984)