Roman Numeral Converter
Convert Arabic integers to Roman numerals (I, V, X, L, C, D, M) and Roman numerals to integers with detailed steps.
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How to Use the Roman Numeral Converter
- 1Type a standard number (e.g. 2026) or a Roman numeral string (e.g. MMXXVI).
- 2The converter automatically detects the input type and converts in real time.
- 3View the breakdown of constituent symbols and subtractive pairs.
- 4Click 'Copy' to copy the converted numeral.
Formula & How It Works
Roman Numeral Values & Rules
Symbols represent values: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Subtractive notation is used for 4s and 9s (IV=4, IX=9, XL=40, XC=90, CD=400, CM=900) to prevent repeating any character more than three times.
Worked Examples
Current Year Conversion
Input: 2026
Explanation: MM (2000) + XX (20) + VI (6) = MMXXVI.
Decoding Roman Numeral
Input: MCMXCIX
Explanation: M (1000) + CM (900) + XC (90) + IX (9) = 1999.
Frequently Asked Questions
Why does 4 use IV instead of IIII?▼
Modern Roman numerals use subtractive notation (IV = 5 - 1 = 4) to ensure no character is repeated four times consecutively.
Is there a Roman numeral for zero?▼
Classical Roman numerals had no symbol for zero. The Latin word 'nulla' was occasionally used instead.
What is the maximum standard Roman numeral?▼
Using standard letters (I, V, X, L, C, D, M), the highest representable number is 3,999 (MMMCMXCIX).
Can I use lowercase roman letters (e.g. mmxxiv)?▼
Yes, our converter is case-insensitive and automatically accepts lowercase and uppercase inputs.
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