Römische Ziffern Konverter

How It Works

1. Enter a number or Roman numeral: Type an Arabic numeral (1–3999) or a Roman numeral string like XIV or MMXXVI.
2. Convert instantly: The tool converts in both directions — Arabic to Roman and Roman to Arabic — automatically detecting the input type.
3. Use the result: Copy the converted value for use in documents, chapter headings, clock faces, or decorative numbering.

Why Use Roman Numeral Converter?

Roman numerals appear in movie sequel titles, book preface page numbers, clock faces, legal document section headings, copyright years, and academic outline formatting. Converting manually involves memorising the subtractive notation rules: IV=4, IX=9, XL=40, XC=90, CD=400, CM=900. This converter handles all valid Roman numeral inputs including the subtractive forms, validates that the input is a proper Roman numeral, and converts any integer from 1 to 3999 (the limit of standard Roman numeral notation).

Roman Numeral Rules

• I, V, X, L, C, D, M — the seven standard symbols (1, 5, 10, 50, 100, 500, 1000)
• Additive notation — VIII = 5+1+1+1 = 8
• Subtractive notation — IV = 5−1 = 4, IX = 10−1 = 9
• Max repetition — a symbol can appear at most 3 times consecutively
• Range — standard notation supports 1–3999

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