How to Use the Roman Numeral Converter
Switch to Number-to-Roman mode and enter any whole number from 1 to 3999 to see its Roman numeral, or switch to Roman-to-Number mode and type a Roman numeral to see its value — the converter validates Roman numeral input by converting it to a number and back, so a malformed numeral is rejected rather than silently misread.
The tool covers both conversion directions, which is useful whether you're decoding a numeral you've encountered or need to write one yourself.
Converting a number to a Roman numeral
As covered in the subtractive-notation guide, the converter applies the standard additive and subtractive rules automatically, so entering something like 1994 correctly produces MCMXCIV rather than a naive but incorrect symbol-repetition approach.
Converting a Roman numeral back to a number
Type the numeral in either case — it's automatically converted to uppercase before being parsed, since Roman numerals are conventionally written in capitals regardless of how you type them in.