This app is able to convert decimal numbers to Roman numerals and vice versa. Just select the appropriate option and enter a valid Roman numeral or decimal number between 0 and 3999. Click convert and your number will be converted to the Roman or the equivalent value in decimal. It's that simple.
To make a successful conversion, you must enter a valid Roman numeral and decimal numbers can only be between 0 and 3999 as Roman numerals only cover that range.