Roman Numerals
Convert between Arabic numbers and Roman numerals. Supports bi-directional conversion for numbers between 1-3999.
Convert between number systems
Our calculator makes it easy to convert between Arabic numbers (1, 2, 3...) and Roman numerals (I, II, III...). Enter either an Arabic number or a Roman numeral, and you'll instantly get the result in the other system. Supports all numbers from 1 to 3999.
How Roman numerals work
Roman numerals use seven basic symbols: I (1), V (5), X (10), L (50), C (100), D (500), and M (1000). By combining these symbols, any number up to 3999 can be expressed. A smaller symbol before a larger one means subtraction (IV = 4), while symbols in descending order are added (VI = 6).
Modern uses today
Although Roman numerals originate from ancient Rome, they are still used today in many contexts. They appear on clock faces, for numbering book chapters, for important years and events (Super Bowl LVIII), in naming royalty and popes, and in classical architecture.
Related calculators
Percentage Calculator
Choose whether you need the value of a percentage or the percentage of a value, then get the exact number instantly.
Temperature Converter
Quickly convert temperatures between Celsius, Fahrenheit, and Kelvin while seeing all three scales at once.
Power converter
Convert between watts, kilowatts, megawatts, horsepower, BTU/h, tons of refrigeration, dBm, and dBW with one input.