How to convert Roman numerals
- To write a number in Roman numerals, type it in the left box. The breakdown below shows how it was built.
- To read a Roman numeral, type it in the right box. The tool also tells you if it is not written in the standard form.
Roman numeral rules
Roman numerals use seven letters: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500 and M = 1000. Values are added from left to right, largest first: VIII = 5 + 1 + 1 + 1 = 8. When a smaller letter comes before a larger one, it is subtracted, but only in six combinations: IV (4), IX (9), XL (40), XC (90), CD (400) and CM (900). A letter is not repeated more than three times in a row, which is why 4 is IV rather than IIII and 40 is XL.
To convert a number, take the largest value that fits, write its letters, subtract and repeat. 1984 = 1000 (M) + 900 (CM) + 80 (LXXX) + 4 (IV) = MCMLXXXIV. Years are usually written this way, for example on film credits and building cornerstones: 2026 is MMXXVI.
The standard system stops at 3,999 (MMMCMXCIX), because larger numbers need a bar over letters to multiply them by 1,000. There is no Roman numeral for zero. Clock faces often use IIII for 4, a traditional exception, so the converter reads it as 4 but notes the standard form.
What is 2026 in Roman numerals?
MMXXVI: two thousands (MM), twenty (XX) and six (VI).
Why can't I convert 4,000 or 0?
Standard Roman numerals have no zero and only reach 3,999 without special overline notation.
Is IIII or IV correct?
IV is the standard form. IIII appears on many clock faces by tradition, but it is not used elsewhere.