Instantly convert between Roman and Arabic numerals
Arabic Number
Roman Numeral
Standard notation supports numbers from 1 to 3999 (MMMCMXCIX).
Roman Symbol Reference
Symbol
Value
Symbol
Value
Symbol
Value
I
1
X
10
C
100
IV
4
XL
40
CD
400
V
5
L
50
D
500
IX
9
XC
90
CM
900
M
1000
Interesting Examples
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Frequently Asked Questions (FAQ)
Roman numerals are a numeral system originating in ancient Rome. It is based on seven symbols: I (1), V (5), X (10), L (50), C (100), D (500) and M (1000). They are still used today on clocks, book chapters, Olympic Games and film titles.
The converter runs entirely in your browser without sending any data to a server. Enter an Arabic number to instantly get the Roman equivalent, or enter a Roman numeral for the reverse conversion.
Standard Roman notation supports numbers from 1 to 3999 (MMMCMXCIX). The number 0 and negative numbers have no representation in the Roman system.
Four is written IV — not IIII. This is the subtractive principle: a smaller numeral placed before a larger one means subtraction. So IV = 5 - 1 = 4, IX = 10 - 1 = 9, XL = 50 - 10 = 40.
Standard Roman numeral rules do not allow a single symbol to be repeated more than three times in a row. Therefore 4 = IV, not IIII. The converter checks these rules automatically.
2025 in Roman numerals is MMXXV. You can click the "2025" button in the examples section to convert it instantly.
CM = 900 (1000 - 100), while DC = 600 (500 + 100). CM uses the subtractive principle, while DC uses addition. The symbol table on this page shows all combinations.
Yes — after conversion a "Copy" button appears which copies the result to your clipboard with a single click.