About this Roman numerals converter
Roman numerals write numbers with seven letters: I for 1, V for 5, X for 10, L for 50, C for 100, D for 500, and M for 1000. Symbols are added from left to right, except that a smaller symbol placed before a larger one is subtracted, as in IV for 4 and CM for 900. This converter works in both directions and decides which way to go for each value, so you can paste a year, a numeral from a clock face, or a whole date. It checks that numerals follow the standard rules and shows how every result is built.
How to convert Roman numerals
- Type a value. Enter a number such as 1994 or a numeral such as MCMXCIV, or press an example.
- Add more values if needed. Separate several values with spaces, dots, hyphens, slashes, or commas, as in a date. The separators are kept in the result.
- Press Convert. Copy the result and read the steps to see how each value was converted.
Frequently asked questions
How do I read a Roman numeral?
Add the symbols from left to right, but subtract a symbol when a larger one comes right after it. MCMXCIV is M (1000) + CM (900) + XC (90) + IV (4) = 1994.
Why is IIII marked as invalid?
Standard Roman numerals never repeat a symbol more than three times and use subtraction instead, so 4 is IV and 9 is IX. Clock faces sometimes show IIII, but it is not the standard form.
Why does the converter stop at 4999?
Without special bar notation, the largest symbol is M for 1000. Standard numerals reach 3999 (MMMCMXCIX), and writing four Ms extends that to 4999, which is as far as plain letters reasonably go.
Is there a Roman numeral for zero?
No. The Roman system had no symbol for zero or for negative numbers, so the converter accepts whole numbers from 1 upward.
How do I write a date in Roman numerals?
Convert the day, month, and year separately and keep the separators. 20-11-2000 becomes XX-XI-MM, and 4.7.1776 becomes IV.VII.MDCCLXXVI.