Roman Numeral Calculator
Decimal → Roman Numeral
Roman Numeral → Decimal
Formula
I=1, V=5, X=10, L=50, C=100, D=500, M=1000
Frequently Asked Questions
How do Roman numerals work?
Roman numerals use letters: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. A smaller numeral before a larger one means subtraction (IV=4, IX=9). Otherwise, add them left to right.