Enter either an Arabic or a Roman numeral and it will be converted into the other. Roman numerals cannot be negative and there is no roman numeral zero. The calculator accepts non-standard roman numerals such as IM and IIII, but such numerals are normalized to their canonical form.

Lowercase letters are used to represent large numbers. This is not standard practice. Often a bar is placed above a Roman digit to indicate that is 1000 times larger than normal. Since letters with bars are not standard characters and computers cannot easily handle them, lowercase is used instead. The maximum number that can be represented in Roman Numerals by this calculator is 3,888,888.