Convert between numbers and Roman numerals
Roman numerals use seven symbols: I (1), V (5), X (10), L (50), C (100), D (500), and M (1000). Numbers are formed by combining symbols additively (VIII = 8) or subtractively—when a smaller symbol precedes a larger one, it's subtracted (IV = 4, IX = 9). The converter applies these rules to translate between systems instantly.
Despite being over 2,000 years old, Roman numerals remain widely used today. You'll find them on clock faces, movie copyright dates (MMXXVI = 2026), Super Bowl numbering, book chapter headings, and architectural cornerstones. Understanding Roman numerals is part of cultural literacy and appears in standardized tests and academic writing.
Only certain subtractive combinations are valid: IV (4), IX (9), XL (40), XC (90), CD (400), and CM (900). You cannot subtract across two levels—IL for 49 is incorrect; the proper form is XLIX. A symbol can repeat up to three times consecutively (III = 3), but never four—that's when subtractive notation kicks in (IV, not IIII).
When converting from Roman to decimal, read left to right. If a smaller value precedes a larger one, subtract it; otherwise, add it. For decimal to Roman, break the number into thousands, hundreds, tens, and ones, then convert each place value. The maximum standard Roman numeral is 3,999 (MMMCMXCIX) since there's no symbol for 5,000.
The basic Roman numerals are: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Combinations follow specific rules: smaller numerals before larger ones are subtracted (IV=4), after are added (VI=6).
Standard Roman numerals can represent numbers 1-3999. 3999 is MMMCMXCIX. Larger numbers historically used different notation systems like vinculum (overlines) to multiply by 1000.
2024 in Roman numerals is MMXXIV. M=1000 (×2 = 2000), XX=20, IV=4. Simply enter the year in our converter to get the Roman numeral representation.