Roman Numeral Converter
Type a number to see its Roman form, or type Roman numerals to get the number. Both directions update live.
Frequently asked questions
What is the largest number this converter handles?
Standard Roman numerals without overlines go up to 3,999 (MMMCMXCIX). This converter supports the conventional range of 1–3999. Numbers above that require special notation (a bar over a numeral meaning “times 1,000”) that is rarely used today.
Why can’t a Roman numeral have more than three of the same letter in a row?
The subtractive rule keeps numbers readable: instead of IIII you write IV (5−1). A fourth repeat is always replaced by a subtractive pair, which is why 4 is IV, 9 is IX, 40 is XL and 90 is XC.
Can Roman numerals represent zero or fractions?
No. The Roman system was developed for counting and accounting, not arithmetic, so it has no symbol for zero and no positional notation. Fractions existed (using a dot for 1/12) but are not part of the standard converter.