Roman Numeral Converter
Convert numbers to Roman numerals and vice versa. Enter a number (1-3999) to see its Roman numeral equivalent, or type a Roman numeral to get the decimal value.
Roman Numeral System
Roman numerals use combinations of letters from the Latin alphabet to represent numbers. The system originated in ancient Rome and was the standard way of writing numbers throughout Europe well into the Middle Ages.
The basic symbols are: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Numbers are formed by combining these symbols, using the subtractive principle where a smaller numeral before a larger one indicates subtraction (IV=4, IX=9, XL=40, etc.).
While Roman numerals are no longer used for everyday math, they remain important in clock faces, book chapters, movie titles, and historical contexts.
Common Roman Numerals
I
= 1
V
= 5
X
= 10
L
= 50
C
= 100
D
= 500
M
= 1000
IV
= 4
IX
= 9
MMXXIV
= 2024
How to Use This Calculator
- Enter a number (1-3999) in the top field to convert to Roman numerals
- Or type a Roman numeral in the bottom field to get the decimal value
- The conversion happens automatically as you type
- See both values displayed together for easy reference