Chiffres romains en nombres

Convert Roman numeral strings to decimal numbers.

Chiffre romain
Valid symbols: I V X L C D M
Nombre
Number will appear here...
Référence rapide
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

Roman Numerals to Numbers Converter

This tool converts Roman numeral strings to their decimal number equivalents. It handles subtractive notation (IV=4, IX=9, XL=40, etc.).

The conversion runs locally in your browser.

How to use

  1. Type or paste a Roman numeral into the input field.
  2. Click Convert to get the decimal number.
  3. Use Copy to copy the result.

What is Roman to Numbers?

The converter reads the Roman numeral string from left to right, adding values. When a smaller value precedes a larger one, it uses subtractive notation.

Input notes

Enter valid Roman numerals using letters I, V, X, L, C, D, M (case insensitive).

Example

Converting Roman numerals to numbers:

--- Roman Input ---
MMXXIV

--- Number Output ---
2024