Number tool
Roman Numerals Converter
Convert any integer from 1 to 3,999 into Roman numerals — or parse a Roman numeral back into a number. Uses the standard subtractive form (IV = 4, IX = 9, XL = 40, etc.).
How the conversion works
Symbols: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Subtractive pairs: IV=4, IX=9, XL=40, XC=90, CD=400, CM=900. Each Roman numeral is the sum of its symbols (after applying subtractive rule).
When you'll use this converter
- Naming popes, monarchs, Super Bowls (Super Bowl LVIII)
- Movie sequels and copyright dates
- Outlines and chapter headings
- Watch dials and clock faces
Frequently asked
Why does this converter stop at 3,999?
Standard Roman numerals only go up to 3,999 (MMMCMXCIX). Larger numbers historically used a 'vinculum' (overline) to multiply by 1,000, but that notation is rarely used today.
Is IIII a valid Roman numeral for 4?
Historically yes (you'll see it on some clock faces), but the modern standard uses subtractive notation: IV.