Roman numerals are still used today in clock faces, book chapters, movie sequels, building cornerstones, and formal numbering systems, but converting between Roman numerals and standard Arabic numbers manually can be tricky for larger numbers. This Roman numeral converter instantly translates numbers in both directions, enter an Arabic number to see its Roman numeral equivalent, or enter a Roman numeral to get its numeric value. It correctly handles the subtractive notation rules (like IV for 4 and IX for 9) that often confuse people learning the system. Useful for students, history enthusiasts, or anyone needing to read or write Roman numerals correctly.