Roman Numeral Converter
Convert between Roman numerals and Arabic (decimal) numbers.
Roman Numeral Symbols
| Symbol | Value | Origin |
|---|---|---|
| I | 1 | Single tally mark |
| V | 5 | Hand with 5 fingers |
| X | 10 | Two Vs (or crossed lines) |
| L | 50 | Half of C |
| C | 100 | Centum (Latin for 100) |
| D | 500 | Half of M |
| M | 1000 | Mille (Latin for 1000) |
Roman Numeral Rules
- Addition: Symbols are added when a smaller value follows a larger one (VI = 5 + 1 = 6)
- Subtraction: A smaller symbol before a larger one is subtracted (IV = 5 - 1 = 4)
- Repetition: A symbol can be repeated up to 3 times (III = 3, but IIII is wrong)
- Only certain subtractions: I before V and X; X before L and C; C before D and M
Common Examples
| Arabic | Roman | Arabic | Roman |
|---|---|---|---|
| 1 | I | 50 | L |
| 4 | IV | 100 | C |
| 5 | V | 500 | D |
| 9 | IX | 1000 | M |
| 10 | X | 2024 | MMXXIV |
| 40 | XL | 3999 | MMMCMXCIX |
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