Roman Numeral
Roman Numeral — runs in your browser. Inputs are not stored.
Roman numeral converter
Enter values, then press Calculate.
Only standard Roman numerals from 1–3999 are supported.
How to use
- In Direction, choose integer → Roman or Roman → integer.
- Enter 2024 or MMXXIV in Input. The default is 2024.
- Press Convert, check the result, and Copy.
- The range is 1–3999. Values 4000 and above, 0, and nonstandard IIII are rejected.
- Lowercase Roman numerals are read as uppercase. Processing is fully client-side.
Key concepts
Roman numeral conversion covers I V X L C D M used for years, chapter numbers, and clock faces. It uses standard subtractive notation: CM (900), CD (400), XC (90), XL (40), IX (9), IV (4). There is no vinculum (overline) for values above 3999. It is a 1–3999 standard converter for years, TOC chapters, and clock faces, keeping IV·IX·XL·XC·CD·CM. Clock-face IIII may be rejected—use IV instead. Nonstandard runs may not parse as integers. Convert year numerals only inside this range.
Nonstandard forms such as IIII and IC are not read as integers. Unlike a number-base converter, this tool only handles decimal ↔ Roman. It works offline. Values 4000+, overline notation, 0, negatives, and nonstandard IIII·IC are rejected. Lowercase is normalized to uppercase before parsing.
Example
Integer → Roman with 2024 yields MMXXIV. 1999 is MCMXCIX; 44 is XLIV. Switch to Roman → integer and type mmxxiv in lowercase to get 2024. 4000 and IIII do not convert. 14 is XIV, 40 is XL, 3999 is MMMCMXCIX. Roman → integer with xiv also yields 14. 88 is LXXXVIII; 49 is XLIX. xliv → 44. MMXXVI is 2026.
Related: Number-base converter
Frequently asked questions
Can I convert Roman numerals 4000 and above?
No. Only 1–3999. A year 4000 is out of range and would need overline notation.
Is lowercase mmxxiv accepted?
Yes. Input is normalized to uppercase and read as the same value.
Is nonstandard IIII allowed?
Nonstandard forms are rejected. Use IV. Clock-face IIII may be rejected.
Can I use this for year numerals?
Yes. Example: 2024 → MMXXIV. Year 2026 is MMXXVI.
Does Roman conversion work offline?
Yes. It is fully client-side and needs no network.
Can 0 or negatives become Roman numerals?
Classical Roman numerals have no 0. This tool only handles positive integers 1–3999.
Last reviewed: 2026-09-04