Roman Numeral Symbols
| Symbol | Value | Symbol | Value |
|---|---|---|---|
| I | 1 | C | 100 |
| V | 5 | D | 500 |
| X | 10 | M | 1,000 |
| L | 50 |
Subtractive Notation Rules
A smaller symbol before a larger one means subtraction. Only I, X, and C can be used as subtractive prefixes.
Roman Numeral Examples
| Decimal | Roman | Decimal | Roman |
|---|---|---|---|
| 1 | I | 40 | XL |
| 4 | IV | 50 | L |
| 5 | V | 90 | XC |
| 9 | IX | 100 | C |
| 10 | X | 400 | CD |
| 14 | XIV | 500 | D |
| 19 | XIX | 900 | CM |
| 20 | XX | 1,000 | M |
| 2026 | MMXXVI | 3,999 | MMMCMXCIX |
Frequently Asked Questions
Why does Roman numeral system stop at 3,999?
Standard Roman numerals use up to three consecutive identical symbols (III, XXX, CCC, MMM). Four M's (MMMM) is non-standard. Numbers above 3,999 were historically written with a bar over a numeral (vinculum) to multiply it by 1,000, but this is rarely used today.
Why is 4 written as IV and not IIII?
Subtractive notation (IV = 4, IX = 9) was standardized in the Middle Ages for clarity and brevity. However, IIII was used historically and still appears on some clock faces — partly for symmetry with VIII on the opposite side, and partly for tradition.
Where are Roman numerals still used today?
Roman numerals appear on clock faces, movie copyright years, Super Bowl numbers (Super Bowl LVIII), book chapter numbering, monarch names (King Charles III), building cornerstones, and academic contexts.