Two tools in one: date-to-Roman-numerals, and number ↔ Roman numeral
Pick any calendar date and this tool instantly renders the day, month, and year as Roman numerals separated by dots - the exact format used for date tattoos, wedding bands, and anniversary gifts. Below it, a two-way converter lets you type any whole number from 1 to 3999 and see its Roman numeral instantly, or type a Roman numeral and get the number back - both update live as you type, with no button to press.
The day.month.year tattoo format
A date like 25 December 2026 becomes XXV . XII . MMXXVI - day, then month, then year, each
rendered separately and joined with dots. This is the conventional layout for Roman-numeral date tattoos and
engravings, which is why the tool keeps the three parts separate instead of converting the date as one combined
number.
Why the limit is 3,999
Standard Roman numerals are built from seven letters - I, V, X, L, C, D, and M - combined by addition and subtraction rules, with no symbol for 5,000 in ordinary use. The largest number representable under the conventional rules is 3999, written MMMCMXCIX, which is why the number converter caps out there.
Built to catch mistakes both directions
Typing a Roman numeral that doesn't follow the standard subtractive rules (like IIII instead of IV) is rejected rather than silently guessed at, since an invalid numeral has no single correct numeric value. The same validation runs when converting a number, so you always get a numeral that round-trips correctly back to the number you started with.