Roman Numeral Converter
Convert between numbers and Roman numerals
π 100% client-side β your data never leaves this pageNumber or Roman
Results
Enter a number or Roman numeral
Quick Reference
I=1
IV=4
V=5
IX=9
X=10
XL=40
L=50
XC=90
C=100
CD=400
D=500
CM=900
M=1000
About this tool
Convert any number (1β3999) to Roman numerals or decode Roman numerals back to decimal. The tool automatically detects whether you entered a number or Roman numeral. Includes a quick reference table for all base Roman numeral values, plus ordinal and binary outputs.
Frequently Asked Questions
What numbers can be expressed as Roman numerals?
Standard Roman numerals represent numbers from 1 to 3999 (MMMCMXCIX). There is no Roman numeral for zero, and numbers above 3999 require non-standard notation.
What are the basic Roman numeral symbols?
I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Subtraction rules apply: IV=4, IX=9, XL=40, XC=90, CD=400, CM=900.
Where are Roman numerals still used today?
Roman numerals appear in clock faces, movie sequel numbering, Super Bowl editions, chapter headings in books, building cornerstones, and formal outlines.