Roman Numeral Converter — Free Online

What Are Roman Numerals?

Roman numerals are a numeral system originating in ancient Rome, using combinations of letters from the Latin alphabet: I (1), V (5), X (10), L (50), C (100), D (500), and M (1000). While largely replaced by the Hindu-Arabic numeral system (0–9) for mathematics, Roman numerals persist in many modern contexts.

Where Roman Numerals Are Still Used Today

• Clock faces — most traditional analog clocks use Roman numerals
• Book chapters and document sections (Chapter II, Section IV)
• Film and TV sequels (Star Wars Episode IV, Super Bowl LVII)
• Copyright years on films, shows, and books (MMXXIV = 2024)
• Royal and papal names (King Charles III, Pope Francis I)
• Outlines and structured lists in academic and legal writing

Roman Numeral Rules

The subtractive principle: when a smaller value precedes a larger one, subtract it (IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900). No symbol repeats more than three times consecutively (III = 3, but 4 = IV not IIII). Large numbers: MM = 2000, MMM = 3000. Standard Roman numerals go up to 3,999 (MMMCMXCIX). Numbers beyond 3,999 use an overline notation.