Roman Numeral Converter

Roman Numeral Converter - Arabic to Roman | Tuttilo

Convert between Arabic numbers and Roman numerals instantly.

Type an Arabic number between 1 and 3999, or enter a Roman numeral using the standard symbols I, V, X, L, C, D, and M. The converter instantly translates in both directions, showing you how ancient Romans would have written modern numbers and vice versa. The tool recognizes subtractive notation where smaller values before larger ones indicate subtraction (like IV for 4 or IX for 9). All processing happens in your browser, making it perfect for quick reference without internet dependency once loaded.

History students translate dates from historical documents that use Roman numerals for years, copyright notices, or chapter numbering in old manuscripts. Graphic designers working on classical or elegant branding need Roman numerals for clock faces, building cornerstones, or formal event invitations like weddings and galas. Movie studios use this to encode production years in film credits — converting release years to Roman numerals for that timeless aesthetic. Writers formatting book manuscripts convert chapter numbers to Roman numerals for front matter sections like prefaces and tables of contents.

Roman numerals follow strict formation rules: never use more than three consecutive identical symbols (except M), and only I, X, and C can be used in subtractive pairs. Valid subtractive combinations are IV (4), IX (9), XL (40), XC (90), CD (400), and CM (900) — other combinations like VL or IC are incorrect. The upper limit of 3999 exists because Romans didn't have a single symbol for 5000, and numbers beyond that used bars over symbols or other special notation not widely standardized. When reading old inscriptions, remember that IIII for 4 appears on some clock faces instead of IV due to aesthetic symmetry preferences.

All processing happens directly in your browser. Your files never leave your device — no server uploads, no cloud storage, no data retention. The tool works offline once loaded, requires no registration, and is completely free with no usage limits.