Convert Arabic numbers to Roman numerals and vice versa.
| Roman | Arabic |
|---|---|
| I | 1 |
| V | 5 |
| X | 10 |
| L | 50 |
| C | 100 |
| D | 500 |
| M | 1,000 |
Only numbers from 1 to 3999 are supported.
Zero and negative numbers cannot be represented in Roman numerals.
Convert between Roman and Arabic numerals
Roman numerals originated in ancient Rome, using 7 symbols (I, V, X, L, C, D, M) to represent numbers. They are still used in clocks, chapter numbers, monarch names, and Super Bowl numbering.
Subtractive notation places a smaller numeral (I) before a larger one (V) to indicate subtraction. However, some clocks use IIII for readability.
Traditional Roman numerals max out at 3999 (MMMCMXCIX). Numbers above 4000 use extended notations like vinculum (a bar above to indicate ×1000).
The Roman numeral system was created before the concept of zero was introduced. Romans didn't need a symbol for 'nothing'.
Understand and apply the Roman numeral system.
Roman numerals use subtractive notation. When a smaller numeral precedes a larger one, it's subtracted (IV=4, IX=9). When it follows, it's added (VI=6, XI=11). The same symbol can repeat up to 3 times (III=3, XXX=30).
Roman numerals are widely used today: clock faces (IV, VIII), book chapters (Chapter III), monarch names (Louis XIV, Pope Francis I), Olympic Games numbering, movie sequels (Rocky II), and more.