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Roman Numeral Converter
Convert numbers to Roman numerals and Roman numerals back to numbers (1–3999). Runs entirely in your browser.
Your inputs never leave your device.
Convert numbers to Roman numerals and Roman numerals back to numbers (1 to 3999). Useful for dates, names, and study.
How to use
- Choose the direction: number to Roman, or Roman to number.
- Enter your value.
- Convert to see the result.
Frequently asked questions
How do Roman numerals work?
They use letters, I, V, X, L, C, D, M, combined by addition and subtraction. For example, IV is 4 and MCMXCIV is 1994. The tool converts both ways.
What's the largest number I can convert?
Standard Roman numerals go up to 3999 (MMMCMXCIX). Numbers above that need special notation the tool doesn't cover.
Does it check my Roman numeral is valid?
Yes, it rejects malformed numerals like 'IIII' and only accepts correctly formed ones.