Roman Numeral Converter

Instantly translate numbers to Roman numerals and vice-versa

Converter Tool

Conversion Breakdown

How It Works

Roman numerals are based on seven distinct symbols. Each symbol represents a specific integer value:

Symbol Value
I1
V5
X10
L50
C100
D500
M1000

Numerals are generally constructed by writing symbols in descending order of value, from left to right. However, to avoid repeating a symbol four times in a row, a subtractive notation is used:

  • I can be placed before V (5) and X (10) to make 4 (IV) and 9 (IX).
  • X can be placed before L (50) and C (100) to make 40 (XL) and 90 (XC).
  • C can be placed before D (500) and M (1000) to make 400 (CD) and 900 (CM).

Because the largest standard Roman numeral is M (1000) and symbols cannot be repeated more than three times, the largest number that can be formed using standard notation is 3999 (MMMCMXCIX).