Roman Numeral Converter
Convert numbers into Roman numerals or decode Roman numerals back into digits, anywhere from 1 to 3999.
How to use the Roman Numeral Converter
- Enter a number to convert to Roman numerals, or type Roman numerals to decode.
- The conversion runs as you type.
- Copy the result.
About the Roman Numeral Converter
Roman numerals use subtractive notation — IV rather than IIII — and only in specific pairs, which is why hand-written conversions of years and chapter numbers so often come out slightly wrong. This converter follows the standard rules in both directions and rejects malformed input, so you can check a tattoo, a clock face or a copyright date with confidence.
Frequently asked questions
How do I write 2026 in Roman numerals?
MMXXVI — two thousands, two tens, a five and a one.
Why is the limit 3999?
Standard Roman numerals have no symbol above M for a thousand, so 3999 (MMMCMXCIX) is the highest number writable without overline notation.
What is subtractive notation?
Placing a smaller numeral before a larger one to subtract it, as in IV for 4 and IX for 9.
Why do Roman numerals stop at 3999?
Standard notation has no symbol above M for a thousand, so the largest number you can write with the usual letters is MMMCMXCIX, or 3999. The Romans used an overline to multiply a numeral by a thousand for larger values, but that convention is not part of the modern standard.
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