Roman Numeral Converter
Convert numbers to Roman numerals and Roman numerals back to numbers.
Reading I, V, X, L, C, D, M
Roman numerals still turn up in clock faces, film credits, book chapters, monarch names and building dates, and reading a long one — or writing a year in them — is genuinely fiddly. This converts a number into Roman numerals and a numeral back into a number, so you can decode a date on a monument or write one correctly without counting on your fingers.
Enter a number or a numeral and see the conversion.
The subtraction rule that trips people
The catch in Roman numerals is the subtraction rule: a smaller symbol before a larger one is subtracted, so IV is four and IX is nine, rather than writing four ones. This keeps numerals shorter but makes them harder to read at a glance. There is also no zero and no simple way to write very large numbers, which is exactly why the system was eventually replaced for arithmetic. For the everyday cases — years, chapters, clock numbers — converting takes the guesswork out.
Common questions
What does IV mean, and why not IIII?
Four. A smaller symbol before a larger one is subtracted, so IV is five minus one — shorter than writing four ones.
Is there a Roman numeral for zero?
No — the system has no zero, one reason it was replaced by decimal numbers for arithmetic.
Is anything uploaded?
No. The conversion happens in your browser.