Roman numeral chart and converter
A complete Roman numeral reference chart plus an interactive converter. Look up individual values (I, V, X, L, C, D, M) and subtractive pairs (IV, IX, XL, XC, CD, CM), then use the converter to translate any number between 1 and 3,999 to or from Roman numerals. All conversion runs locally in your browser.
How it works
To convert a number to Roman numerals, the tool repeatedly subtracts the largest possible Roman numeral value from the number and appends the corresponding symbol (including subtractive pairs like IV=4, IX=9, XL=40, XC=90, CD=400, CM=900). To convert Roman numerals to a number, each character is mapped to its value; a character is subtracted if the next character has a greater value. All processing runs in JavaScript in your browser.
Processing runs in your browser
All conversions happen locally in your browser tab. Our servers are not involved at any point.
Related operations
For working with fractional or mixed numbers, try the fraction calculator. To convert numbers between binary, hex, and decimal, use the number base converter. For unit conversions like inches to centimetres, see the unit converter.
Frequently asked questions
- What are the 7 basic Roman numeral symbols?
- I=1, V=5, X=10, L=50, C=100, D=500, M=1000. These seven symbols are combined and sometimes subtracted to form any number from 1 to 3,999.
- What are the subtractive pairs?
- IV=4, IX=9, XL=40, XC=90, CD=400, CM=900. These six pairs use a smaller value before a larger to indicate subtraction. Only these specific pairs are valid. For example, IC (1 before 100) is not standard.
- How do you write years in Roman numerals?
- Write each digit group separately. 2024: 2000=MM, 24=XXIV, so MMXXIV. 1999: 1000=M, 900=CM, 90=XC, 9=IX, so MCMXCIX.
- Is my data sent to a server?
- All conversions run locally in your browser. No data is sent to our servers.