Roman Numeral Converter
How to use
- Choose Number to Roman, Roman to Number, or Date.
- Type your value. The answer updates as you type, and invalid numerals are flagged with the reason.
- In Date mode, enter a date as MM/DD/YYYY and pick a separator.
How it works
Roman numerals use seven letters: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500 and M = 1000.
Letters are written from largest to smallest and added up. A smaller letter placed before a larger one is subtracted, but only in six pairs: IV (4), IX (9), XL (40), XC (90), CD (400) and CM (900).
A letter never repeats more than three times in a row, which is why the standard range stops at 3999 (MMMCMXCIX).
FAQ
Why is IIII marked as invalid?
Standard notation writes 4 as IV. You will see IIII on some clock faces, but it is a decorative tradition rather than the accepted form.
How do I write 2026 in Roman numerals?
2026 is MMXXVI: MM for 2000, XX for 20 and VI for 6.
Is there a Roman numeral for zero?
No. The Roman system has no symbol for zero, so the converter starts at 1.
How should I format a date for a tattoo?
Most people convert month, day and year separately and join them with dots or spaces, for example VII.IV.MDCCLXXVI for July 4, 1776. Check the order (US or day first) before you commit.