◨ CALCULATORS Updated July 25, 2026

Roman Numeral Converter

Convert between Arabic numbers and Roman numerals.

Number (1-3999)
Result
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How it works

Numbers are converted with the standard subtractive notation — 4 is IV, 9 is IX, 40 is XL — using the classic values I, V, X, L, C, D, and M. Decoding reads the numeral left to right and subtracts any smaller value that precedes a larger one.

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Frequently asked questions

Why is the maximum 3999?

Standard Roman numerals have no symbol above M (1000), so 3999 (MMMCMXCIX) is the largest value writable without overlines.

Is there a Roman zero?

No. The system has no symbol for zero or for negative numbers.

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