Roman Numeral Converter
Convert between Arabic numbers and Roman numerals (1–3,999).
Roman Numeral Reference
Frequently Asked Questions
What are the basic Roman numeral symbols?▼
There are 7 symbols: I (1), V (5), X (10), L (50), C (100), D (500), M (1000). All other numbers are formed by combining these — for example, VIII = 5+3 = 8, and IX = 10−1 = 9.
What is the subtractive notation rule?▼
When a smaller numeral appears before a larger one, it is subtracted. Only six forms are valid: IV (4), IX (9), XL (40), XC (90), CD (400), CM (900). For example, 1999 = MCMXCIX = 1000 + (1000−100) + (100−10) + (10−1).
Why can't you write numbers above 3,999 in standard Roman numerals?▼
Standard Roman numerals have no symbol larger than M (1,000), so the largest without extension is MMMCMXCIX (3,999). Historical extensions used a bar over a numeral to multiply by 1,000, but these are non-standard today.
What year is MMXXIV?▼
MMXXIV = 2000 + 20 + 4 = 2024. MM = 2000, XX = 20, IV = 4.