Convert Arabic numbers to Roman numerals or Roman numerals back to numbers. A second mode handles dates and multiple values while preserving their separator.
Examples
LXIII
L + X + I + I + I = 50 + 10 + 1 + 1 + 1 = 63.2026/09/13
The date converts to MMXXVI/IX/XIII.
Vinculum
Enter
_V for 5,000. The converter supports values through 3,999,999.Formula
Symbols normally add from largest to smallest. A smaller valid symbol before a larger one subtracts:
IV = 5 − 1, IX = 10 − 1, XL = 50 − 10, XC = 100 − 10, CD = 500 − 100, and CM = 1,000 − 100.Roman numeral conventions varied historically. This converter enforces the common modern subtractive form so every number has one unambiguous representation.
Notation limits
The converter uses the modern subtractive convention for positive integers in its supported range. Historical Roman inscriptions used several additive and nonstandard forms, and there is no single ancient convention for zero, negative numbers, fractions, or very large values. A valid modern conversion therefore need not reproduce a historical inscription exactly.