Roman Numeral Converter
Convert between Roman numerals and Arabic numbers
Basic Symbols
Advanced Symbols
Subtractive Notation
More Examples
🌈 Browse More Tools
Complete Guide: Roman Numeral Converter
Everything you need to know about using this tool effectively
The Roman Numeral Converter transforms numbers between standard Arabic numerals (1, 2, 3) and Roman numerals (I, V, X, L, C, D, M). You enter a number and get the Roman numeral equivalent, or enter a Roman numeral and get the number. It supports values from 1 to 3,999. All processing happens in the browser.
This tool maps numbers to Roman numeral notation using the standard subtractive principle (IV for 4, IX for 9, etc.). It also parses Roman numerals back to numbers by recognizing the patterns. The algorithm processes from largest to smallest numeral value.
Reading Roman numerals on monuments
Enter MCMXCIX to find it means 1999.
Numbering chapters or outlines
Convert chapter numbers to Roman numerals for a formal document outline.
Clock and watch reading
Convert numbers to Roman numerals to understand analog clock faces.
Super Bowl or event numbering
Convert Super Bowl LVIII to 58.
Enter a number or Roman numeral
Type in either field. The tool converts in both directions.
View the result
The conversion appears instantly.
Copy the result
Copy the converted value.
Roman numerals: I=1, V=5, X=10, L=50, C=100, D=500, M=1000.
Subtractive notation: IV=4, IX=9, XL=40, XC=90, CD=400, CM=900.
The maximum standard Roman numeral is MMMCMXCIX (3,999).
Roman numerals do not have a zero.
What range of numbers is supported?
The converter supports numbers from 1 to 3,999, which is the standard range for Roman numerals.
How does subtractive notation work?
When a smaller numeral appears before a larger one, it is subtracted. IV is 5-1=4. IX is 10-1=9. XL is 50-10=40.
Is my data sent to a server?
No. All conversion happens in your browser. Nothing is transmitted.
Can I convert Roman numerals to numbers?
Yes. Enter a Roman numeral in the Roman field and the tool shows the number.
Why is the maximum 3,999?
Standard Roman numerals cannot represent numbers above 3,999 without using additional notation like overlines for multiplication by 1,000.