About the Roman Numeral Converter
The Roman Numeral Converter uses standard subtractive notation such as IV, IX, XL and CM. Decode mode re-encodes the result to reject non-canonical arrangements.
How to use the Roman Numeral Converter
- Enter a whole number or Roman numeral.
- Choose the conversion direction.
- Convert and verify the canonical representation.
Practical tips
- Standard compact Roman numerals usually cover 1 through 3999.
- Enter letters without spaces; lowercase is accepted and normalized.