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Roman Numerals

Type a number or a Roman numeral to convert instantly — then try the quiz below.

Converter

Quiz — 10 questions

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How Roman numerals work

Seven letters carry all the values: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Values add from left to right (VIII = 8), but a smaller value before a larger one subtracts (IV = 4, IX = 9, XL = 40, CM = 900) — only I, X and C can be used that way. Numerals still appear on clock faces, book chapters, movie sequels and events like Super Bowl LVIII, so reading them fluently is a small skill that keeps paying off. The quiz mixes both directions and gets you fluent fast.

Frequently asked questions

How do you write 2026 in Roman numerals?
MMXXVI — M+M (2000) + X+X (20) + V+I (6). Other handy ones: 4 = IV, 9 = IX, 40 = XL, 90 = XC, 400 = CD, 900 = CM, 1999 = MCMXCIX.
Why does the converter only go up to 3999?
Standard Roman numerals repeat a letter at most three times, so MMMCMXCIX (3999) is the largest normal form. The Romans wrote bigger numbers with a bar over letters (V̄ = 5000), but that notation isn't standard today.
Why is 4 written IV and not IIII?
Subtractive notation (IV = 5−1) became the standard because it's shorter. Fun exception: many clock faces still use IIII for visual balance with VIII on the opposite side of the dial.