Roman Numeral Date Converter
Convert an integer from 1–3999 or a date such as 2026-08-29 into classic Roman numerals.
Keyboard: Ctrl or ⌘ + Enter copies. Escape clears. Text stays in this browser.
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Integers 1–3999 and ISO-style dates
Classic Roman numerals cover 1 through 3999 (I to MMMCMXCIX). A date like 2026-08-29 is expanded into year, month, and day numerals. Additive and subtractive notation follows the usual IV, IX, XL, XC, CD, CM rules.
Outlines, clocks, and super bowls
Use it for chapter numbers, clock faces, and event titles that expect Roman years. Number to Words is the tool for cheque amounts. A1Z26 is a letter-index cipher, not Roman.
Year zero and large years
There is no Roman zero; values outside the supported range are rejected or left unchanged. Unicode “Roman numeral” characters (ⅰ, ⅻ) are not the same as ASCII I/V/X output. Conversion stays in the browser.
Frequently asked questions
Why is 4 written as IV not IIII?
Standard subtractive notation uses IV. Clock faces sometimes still use IIII; this converter follows the textbook form.
Can I convert Roman numerals back to digits?
Paste I, V, X, L, C, D, M sequences to decode when they form a valid numeral.
Does it support Unicode Ⅿ or Ⅰ?
Input is aimed at ASCII I, V, X, L, C, D, M. Fancy numeral letters may not parse.