Roman Numeral Converter

The seven Roman numerals

Roman numerals use seven letters: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1,000. Write the values from largest to smallest and add them: MDCLXVI = 1000 + 500 + 100 + 50 + 10 + 5 + 1 = 1,666.

The subtraction rule

A smaller numeral placed before a larger one is subtracted. Only six pairs are allowed: IV (4), IX (9), XL (40), XC (90), CD (400) and CM (900). So 1994 is MCMXCIV (1000 + 900 + 90 + 4) — not MDCCCCLXXXXIIII. A numeral is never repeated more than three times in a row, and V, L and D are never repeated. The converter flags non-standard forms like IIII or IC and shows the correct one.

Numbers above 3,999

Standard numerals stop at 3,999 (MMMCMXCIX). For larger numbers a bar over a numeral — the vinculum — multiplies it by 1,000: V is 5,000 and X is 10,000. The converter uses vinculum for numbers up to 3,999,999. There is no Roman numeral for zero.

Years and dates

Films and buildings often show the year: 2026 is MMXXVI, 2000 is MM and 1999 is MCMXCIX. For tattoos and wedding dates each part is converted separately — 14 · 02 · 2026 becomes XIV · II · MMXXVI. Double-check the order (month first in the US, day first in most other countries) before anything permanent.

Tools that pair well with the Roman Numeral Converter

• Number to Words Converter — Spell out any number in words — “one thousand two hundred thirty-four” — as a cardinal, an ordinal (“twenty-first”) or a check amount (“One thousand two hundred and 50/100 dollars”).
• Number Base Converter — Type a number in any base and see it in all the others instantly.
• Date Difference Calculator — Count the days between two dates — including business days and a years/months/days breakdown — add or subtract time from a date, or run a live countdown.
• Age Calculator — Enter a date of birth to get the exact age in years, months and days — plus total days and weeks lived, the weekday you were born on, a countdown to the next birthday and your star sign.