Roman Numeral Converter – Numbers to Roman Numerals

Enter a number or Roman numeral to convert
Roman Numeral Reference Chart
Basic Roman Numerals Arabic Roman Arabic Roman Arabic Roman 1 I 10 X 100 C 2 II 20 XX 200 CC 3 III 30 XXX 300 CCC 4 IV 40 XL 400 CD 5 V 50 L 500 D 6 VI 60 LX 600 DC 7 VII 70 LXX 700 DCC 8 VIII 80 LXXX 800 DCCC 9 IX 90 XC 900 CM 1000 = M

Roman Numeral Converter Guide

This calculator provides a seamless way to convert standard Arabic numerals into Roman numerals and vice versa. The tool supports numbers in the range of 1 to 3,999.

Conversion Principles

Roman numerals are based on seven symbols, each with a specific value:

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

The system uses two main principles:

  1. Additive Notation: Symbols are added together when placed from left to right in order of decreasing value. For example, VI = 5 + 1 = 6, and LXX = 50 + 10 + 10 = 70.
  2. Subtractive Notation: A smaller value symbol placed before a larger value symbol is subtracted. This applies to specific pairs:
    • IV (4), IX (9)
    • XL (40), XC (90)
    • CD (400), CM (900)

Usage Examples

Here are some examples of conversions you can perform with this calculator:

Input Value Resulting Output Note
1984 MCMLXXXIV Converts a standard number to Roman.
MMXXV 2025 Converts a Roman numeral to a number.
42 XLII Demonstrates subtractive (XL) and additive (II) notation.
XCIX 99 Shows two subtractive pairs (XC and IX).
3999 MMMCMXCIX The highest number supported by standard Roman numerals.
DCCLXXXVIII 788 A complex number using only additive notation.
444 CDXLIV Combines three subtractive pairs.
1066.75 MLXVI Decimal part is ignored for Roman numeral conversion.
LV 55 Simple additive conversion.
MCMXCIX 1999 Converting a number with multiple subtractive notations.