Free online Roman numerals converter. Convert any number (1-3999) to Roman numerals and vice versa. Includes a complete Roman numeral chart. 100% client-side, instant results.
Common Roman numerals and their values
Our Roman numerals converter provides instant bidirectional conversion between Arabic numbers and Roman numerals. Whether you are studying history, solving puzzles, or simply curious, this tool makes Roman numeral conversion effortless. All processing happens in your browser — no data sent to any server.
Roman numerals are a numeral system that originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages. Numbers are represented by combinations of letters: I, V, X, L, C, D, and M.
This converter supports numbers from 1 to 3999. Standard Roman numerals don't have a symbol for zero, and numbers above 3999 require special notation with vinculum (overline) which is not commonly used.
Yes! Our converter works both ways. Enter a Roman numeral like "MCMXCIV" and it will instantly convert to 1994. Enter 1994 and it will show "MCMXCIV".
The ancient Romans did not have a concept of zero as a number. They used the word "nulla" (meaning "none") in contexts where zero was needed. The concept of zero as a number was introduced to Europe from India via the Arab world much later.
The number 3888 (MMMDCCCLXXXVIII) is the longest valid Roman numeral using standard notation, with 15 characters. Our converter handles it instantly.