Roman Numeral Converter
Convert between Arabic numbers and Roman numerals instantly. Supports 1–3999 with a detailed symbol breakdown. Free online tool.
How to Use
Choose a conversion direction
Use 'Number → Roman' to convert an Arabic number to Roman numerals, or 'Roman → Number' to decode a Roman numeral.
Enter a value
Type in the input field. Results update in real time. Arabic numbers must be between 1 and 3999.
Copy the result
Click Copy to copy the result to your clipboard. The symbol breakdown shows exactly which symbols were used.
FAQ
- Roman numerals use 7 symbols: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Symbols are written from largest to smallest and added together. When a smaller symbol appears before a larger one, it is subtracted (IV=4, IX=9, XL=40, XC=90, CD=400, CM=900).
- Standard Roman numerals go up to 3999 (MMMCMXCIX). Numbers above 3999 require a vinculum (overline) system that is rarely used today. This tool supports the standard 1–3999 range only.
- Roman numerals appear on clock faces, movie copyright years (© MMXXIV), book chapter and preface page numbers, Olympic Games edition numbers (e.g. XXXIII Olympiad), royal names (Henry VIII), and music theory chord progressions (II-V-I).
- Both have historical precedent, but 'IV' is the modern standard. 'IIII' was common in ancient Roman inscriptions and still appears on some clock faces for visual symmetry. This tool uses modern subtractive notation (IV, IX, XL, etc.).