Roman Numerals Converter
Convert between Arabic numbers and Roman numerals. Enter a number (1–3,999) or a Roman numeral to convert instantly.
How Roman Numerals Converter works
Roman numeral symbols
Roman numerals use seven symbols: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1,000. Numbers are formed by combining these symbols. When a smaller symbol appears before a larger one, it is subtracted (e.g. IV = 4). When a smaller symbol appears after a larger one, it is added (e.g. VI = 6).
Subtractive notation
Six subtractive combinations are standard: IV (4), IX (9), XL (40), XC (90), CD (400), CM (900). These are the only valid subtractive pairs — you never write IC for 99 (it is XCIX) or VL for 45 (it is XLV). Each symbol can only be subtracted from the next two higher-value symbols.
Conversion algorithm
To convert a number to Roman numerals: start with the largest symbol value (M = 1000). Subtract it repeatedly while the remainder is >= that value, appending the symbol each time. Move to the next symbol value and repeat. For example, 2024: M (1000, remainder 1024), M (1000, remainder 24), X (10, remainder 14), X (10, remainder 4), IV (4, remainder 0) = MMXXIV.
Range limits
Standard Roman numerals represent numbers from 1 to 3,999. There is no symbol for zero, and numbers above 3,999 historically required a bar (vinculum) above a symbol to multiply it by 1,000. This converter handles the standard range of 1–3,999.
Frequently asked questions
What is 2024 in Roman numerals?
2024 in Roman numerals is MMXXIV. M = 1000 (×2 = 2000), X = 10 (×2 = 20), IV = 4. Total: 2000 + 20 + 4 = 2024.
What is 2025 in Roman numerals?
2025 in Roman numerals is MMXXV. M = 1000 (×2 = 2000), X = 10 (×2 = 20), V = 5. Total: 2000 + 20 + 5 = 2025.
How do I read Roman numerals?
Read from left to right. Add each symbol's value unless a smaller symbol precedes a larger one — then subtract. For example, MCMXCIV: M (1000) + CM (900) + XC (90) + IV (4) = 1994.
Why is 4 written as IV and not IIII?
Subtractive notation (IV = 4) is the standard modern convention because it is shorter. However, IIII is still used on many clock faces — this is called the "watchmaker's four" and persists for aesthetic balance (IIII visually mirrors VIII on the opposite side of the dial).
What is the largest number in Roman numerals?
Using standard notation, the largest number is 3,999 (MMMCMXCIX). Numbers above 3,999 historically used a vinculum — a bar above a numeral that multiplies its value by 1,000. For example, V̅ = 5,000. This converter supports 1–3,999.
Is there a Roman numeral for zero?
No. The Roman numeral system has no symbol for zero. The concept of zero as a number was introduced to Europe via Arabic mathematicians in the Middle Ages, long after the Roman system was established.
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