Roman Numeral Converter
Converts between regular numbers and Roman numerals. Type a number (1 to 3999) to get the Roman numeral, or enter a Roman numeral to convert it back. Covers everything from I to MMMCMXCIX.
How to use
- Pick a direction: number to Roman numeral or Roman numeral to number.
- Enter a number between 1 and 3999, or type the Roman numeral.
- Copy the result. The breakdown of each numeral is shown too.
Related tools:
Roman numerals use seven symbols: I (1), V (5), X (10), L (50), C (100), D (500), M (1000). Numbers are formed by combining these - XLVII is 47 (40+5+2). The subtractive notation (IV for 4, IX for 9, XL for 40, CM for 900) was standardised in medieval Europe even though the ancient Romans used IIII and VIIII in many inscriptions.
They show up more often than expected: movie release years (MMXXIV = 2024), Super Bowl numbers, clock faces, outline numbering in documents, chapter headings, and names of monarchs and popes (Henry VIII, Pope John XXIII). The converter handles both directions up to 3,999 (MMMCMXCIX).
Frequently Asked Questions
Why do Roman numerals stop at 3,999?
The standard Roman system uses a maximum of three consecutive identical symbols (so MMM = 3,000 is the highest M value). There is no standard symbol for 5,000 in the classic system, making 3,999 (MMMCMXCIX) the largest standard number. Extended systems use overlines to represent thousands multiplied, but those are not universal.
Is there a year 0 in Roman numerals?
No. The Romans had no concept of zero. Years go from 1 BC to 1 AD with no year zero, which is one reason calculating durations across BC/AD requires care.
What year is MCMXCIX?
1999. M=1000, CM=900, XC=90, IX=9. Add them: 1999.