Roman Numeral Converter
Convert integers 1–3999 to Roman numerals or validate Roman numeral input.
Calculations run in this browser. Values are not submitted to the server.
Result
Formula and assumptions
Uses canonical subtractive notation (IV, IX, XL, XC, CD, CM). Roman values are limited to 1–3999.
Example values are shown in the input placeholders. Results use browser number precision unless the tool uses exact integer arithmetic. Check units and assumptions before using a result.