Converts between numbers and Roman numerals (1–3999).
Roman Numerals is a free converter that turns regular numbers into Roman numerals and parses Roman numerals back into numbers. It supports the standard range from 1 to 3999, validating input in both directions so you only get well-formed results. Pick a direction and convert values like 2024 to MMXXIV or read a numeral such as MCMLXXXIV back to its decimal value.
No. The conversion runs entirely in your browser using local JavaScript, and nothing you type is uploaded or stored on any server.
Numbers from 1 to 3999 (integers only). Values outside that range, decimals, or non-numeric input produce an error message because standard Roman numerals do not include zero, negatives, or values of 4000 and above.
Only the letters M, D, C, L, X, V, and I are accepted, in any letter case. Input is trimmed and uppercased automatically, but any other character is rejected as invalid.
The tool enforces standard subtractive notation, so it round-trips your input and rejects non-canonical forms. For example IIII, VV, or IC are invalid because the correct numerals are IV, X, and XCIX respectively.
Use the Mode option to choose Number to Roman or Roman to Number, then enter your value. The conversion updates based on the selected direction.