Roman Numeral Converter
Convert numbers to Roman numerals and back — the direction is detected, mistakes like IIII or IC are explained with the correct form, and dates, big numbers (overline) and lists are supported.
- Your data never leaves your device
- 100% free
- No sign-up
- Works offline after first load
How to use the roman numeral converter
- Type a number (like 1987) or a Roman numeral (like MCMLXXXVII).
- The conversion, the breakdown and any correction appear instantly.
- Convert a date or a whole list, or use the chart for quick reference.
About Roman Numerals
Convert numbers to Roman numerals and back. Everything is worked out in your browser and updates as you type.
The result comes with the other forms you might need, a table to copy or download, and the working shown step by step. You can share a link to your conversion, keep a history and print the result.
Good for
- Tattoos, engravings and wedding dates
- Book chapters, outlines and movie years
- Clocks, monarchs and Super Bowl numbers
Tip: Type a date like 15/10/2026 to get it in Roman numerals for a tattoo or invitation.
Frequently asked questions
How do Roman numerals work?
I = 1, V = 5, X = 10, L = 50, C = 100, D = 500 and M = 1000. Symbols are added from left to right, but a smaller one before a larger one is subtracted: IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900.
What is the largest Roman numeral?
With the standard symbols, 3,999 (MMMCMXCIX). A bar over a letter multiplies it by 1,000, which this converter uses up to 3,999,999.
Is IIII correct?
Not in the standard form — a symbol is used at most three times in a row, so 4 is IV. (IIII still appears on some clock faces.) The converter reads it and shows the standard form.
How do I write a date in Roman numerals?
Type it as DD/MM/YYYY — 15/10/2026 becomes XV.X.MMXXVI. Choose dots, slashes, dashes or spaces between the parts.
Is there a Roman numeral for zero?
No — the Romans had no numeral for zero; medieval writers used the word “nulla” or the letter N.