Roman Numeral Converter

Translation between standard Arabic numbers (1-3999) and their Roman numeral equivalents runs in both directions here. Historians, designers working in traditional numbering, and casual readers all run into Roman numerals, on clock faces, in copyright lines, and in the dates shown in film credits. Reading them often comes down to deciphering an old document or simply pinning down a release year.

Seven basic symbols carry the system: I (1), V (5), X (10), L (50), C (100), D (500), and M (1000). It combines additive and subtractive rules, so VI reads as 5+1=6 while IV reads as 5-1=4. The algorithm steps through your input, Arabic or Roman, weighing each value against its position to convert accurately in either direction across the range 1 to 3999.

There is no Roman symbol for zero, and the system handles neither negative numbers nor fractions. Subtractive symbols never repeat, so 8 is VIII, not IIX; only a single smaller numeral may sit before a larger one to signal subtraction. Keep any Arabic input within 1 to 3999, since values outside that band have no standard Roman form.