Roman numeral converter
What is a Roman Numeral Converter?
Roman numerals are still used for clock faces, book chapters, film copyright years, monarch and pope names, Super Bowl numbers and outline numbering. This converter translates between ordinary numbers and Roman numerals in both directions and checks that a numeral is written correctly.
How to use it
- Enter a number from 1 to 3999 to get its Roman numeral.
- Or enter a Roman numeral to get its value.
The symbols
I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000.
The rules
- Symbols are written from largest to smallest and added:
VIII= 5 + 3 = 8. - A smaller symbol before a larger one is subtracted. Only six pairs are standard: IV (4), IX (9), XL (40), XC (90), CD (400) and CM (900).
- A symbol repeats at most three times in a row, so 4 is IV, not IIII (although many clock faces use IIII).
Worked examples
- 2026 = 2000 + 20 + 6 = MM + XX + VI = MMXXVI.
- 1994 = M + CM + XC + IV = MCMXCIV.
- 3999 = MMMCMXCIX, the largest value in standard notation.
- XLII = 40 + 2 = 42.
Common mistakes
ICfor 99 is not standard; writeXCIX.VXfor 5 is invalid; V, L and D are never subtracted.- There is no Roman numeral for zero. Larger numbers used a bar over a symbol to multiply it by 1000, which is outside standard notation.
Frequently Asked Questions
How do you write 2026 in Roman numerals?
MMXXVI: two thousand (MM), twenty (XX) and six (VI).
Why is 4 written as IV and not IIII?
Standard notation uses subtraction to avoid repeating a symbol four times. Clock faces are a traditional exception.
What is the largest Roman numeral?
In standard notation, 3999, written MMMCMXCIX.
Is there a Roman numeral for zero?
No. The Roman system had no symbol for zero.