Tool
Roman Numeral Calculator
Add, subtract, multiply, or divide using Roman numerals, Arabic numbers, or both. Results use canonical Roman numerals in the standard 1–3999 range.
Example: XLIX + LI → 49 + 51 = 100 → C
How it works
Values are converted to Arabic integers, the operation is applied, and a canonical Roman numeral is returned when the result is between 1 and 3999. Zero, negatives, and results above 3999 are explained instead of inventing invalid notation.
Ancient Romans often calculated with counting boards or abaci; this tool is a modern teaching/conversion calculator. Read the arithmetic guide for context.