How to use
Type a regular number to get its Roman numeral, or type a Roman numeral (upper or lower case) to get the number. The direction is detected automatically.
How Roman numerals work
The symbols are I = 1, V = 5, X = 10, L = 50, C = 100, D = 500 and M = 1000. Symbols usually go from largest to smallest and are added up: XV = 15. When a smaller symbol comes before a larger one, it’s subtracted: IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900.
No symbol repeats more than three times in a row, so standard notation covers the numbers from 1 to 3,999.
Examples
- 2026 = MMXXVI.
- 1994 = MCMXCIV.
- 3999 = MMMCMXCIX, the largest number in standard notation.
- XIV = 14, XL = 40.
FAQ
Why isn’t IIII accepted? It’s a non-standard form (you’ll sometimes see it on clock faces). The converter checks for the standard form: 4 = IV.
Is there a zero in Roman numerals? No — Roman numerals have no zero and no negative numbers.