Roman Numeral Converter

About Roman Numeral Converter

Convert between Roman numerals and ordinary numbers, both ways, on one screen. Type a number (1-3999) and the Roman version updates as you go; type a Roman numeral (any combination of M D C L X V I) and the number updates. Strict validation rejects invalid forms like IIII or IL with a friendly explanation, so it doubles as a teaching aid for the rules. A breakdown panel below shows how the value decomposes (MCMLXXXIV = M + CM + LXXX + IV = 1000 + 900 + 80 + 4) and a built-in cheat sheet lists the seven symbols plus the six subtraction pairs. Useful for kids learning the system, anyone reading film credits or chapter titles, or quick checks when writing dates and outlines.