Arabic → Roman
—
Roman → Arabic
—
Quick Reference
I
1
V
5
X
10
L
50
C
100
D
500
M
1000
What This Tool Does
Converts between Arabic numbers (1–3,999) and Roman numerals in both directions. Results update live as you type. The quick reference table shows the 7 base symbols and their values.
Frequently Asked Questions
What numbers can be converted?
Standard Roman numerals represent numbers from 1 (I) to 3,999 (MMMCMXCIX). Numbers larger than 3,999 traditionally required a bar over a numeral to multiply it by 1,000, which is not supported in standard notation.
What are the Roman numeral symbols?
I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Subtractive notation is used for 4 (IV), 9 (IX), 40 (XL), 90 (XC), 400 (CD), and 900 (CM).
What is subtractive notation?
When a smaller value symbol appears before a larger one, it is subtracted rather than added. So IV = 5−1 = 4, and IX = 10−1 = 9. This avoids writing IIII for 4 and keeps numerals shorter.