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Roman Numeral Converter

Convert numbers to Roman numerals and back - auto-detects direction.

How to use

  1. Type a number or a Roman numeral - direction is detected automatically.
  2. Read the conversion instantly.
  3. Copy the result.

Frequently asked questions

Why only up to 3999?

Standard Roman notation has no symbol above M (1000) and repeats a symbol at most three times - larger numbers used overlines, which don't type well.

Why is 4 written IV?

Subtractive notation: a smaller numeral before a larger one is subtracted - IV = 5−1, IX = 10−1, XL = 40, CM = 900.

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