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Roman Numeral Conversion

Roman numeral converter tool. Convert Arabic numbers (1-3999) to Roman numerals or Roman numerals to Arabic numbers.

Arabic Number
Result
Read Only

How to use

About this tool

Converts between Roman numerals (I, V, X, L, C, D, M) and Arabic numbers.

How to use

Enter Roman numerals or a number; the other form is shown.

Use cases

β€’ Format conversion β€’ Copyright/chapter numbers β€’ Education and quizzes β€’ Legacy numbering

FAQ

Q: What is the valid range for conversion?
A: Standard Roman numerals range from 1 (I) to 3999 (MMMCMXCIX). Numbers outside this range cannot be expressed in classical Roman notation.
Q: Why does 4 become IV instead of IIII?
A: Roman numerals use the subtractive notation: when a smaller value precedes a larger one, the smaller is subtracted. IV means 5 βˆ’ 1 = 4. This convention has been standard since medieval times.
Q: Can I convert Roman numerals back to Arabic numbers?
A: Yes. Enter Roman numerals (e.g., XIV) and the tool outputs the corresponding Arabic number (14).
Q: Are lowercase roman numerals accepted?
A: Yes. Lowercase input (e.g., xiv) is accepted and treated the same as uppercase.
Q: Does this tool send my data to a server?
A: No. All conversion is performed in the browser. No data is sent to any server.