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Roman Numeral Converter

Convert integers to Roman numerals or Roman numerals back to integers. Supports 1–3,999. Shows standard notation (MCMXCIX) instantly as you type.

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Roman Numeral Converter: questions

What is the largest Roman numeral?
Traditional Roman numerals go up to 3,999 (MMMCMXCIX). Numbers above 3,999 require overlines or other extensions not in standard notation.
Why does IV equal 4?
Subtractive notation: a smaller numeral before a larger one means subtraction. IV = V(5) - I(1) = 4. This rule applies to IX, XL, XC, CD, CM as well.
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