Roman numerals converter
Convert numbers to Roman numerals and back, from I to MMMCMXCIX.
How to use
- Choose a direction: Number → Roman or Roman → Number.
- Type or paste values, one per line for batch conversion.
- Invalid entries show as "?" — fix them and the result updates instantly.
Frequently asked questions
Why is the range limited to 1–3999?
Standard Roman notation has no symbol for zero and no agreed way to write 4000+ without overline notation, which plain text cannot represent reliably.
Is IIII accepted for 4?
No. The converter follows strict subtractive notation, so 4 is IV. Clock faces that use IIII are a stylistic exception, not standard notation.
Does lowercase input work?
Yes. "mcmxciv" parses the same as "MCMXCIV"; output is always uppercase.
About this tool
Roman numerals never quite left us: they number movie sequels and Super Bowls, mark book chapters and clock faces, and date building façades and film credits. This converter translates both directions — type 2024 to get MMXXIV, or paste MCMXCIV to get 1994. It validates strictly, so malformed sequences like IIII or VX are flagged rather than guessed at, and it handles the standard range of 1 to 3999 (classical notation has no zero and no clean way past 3999). Paste one value per line to convert a whole list, for instance a column of chapter numbers.