X→10

Roman Numeral Converter

Convert Roman numerals to decimal values or decimal values to Roman numerals.

Interactive visual

See how the Roman Numeral Converter works

X→10

XLII

XLII ↔ 42

Live input

XLII or 42

Live output

Updates as you type

Enter a Roman numeral or whole number

Example: XLII ↔ 42

Converted value

—

Provide input

Validate format

Return converted value