Roman Numeral Converter
Convert Arabic numbers to Roman numerals and back, from 1 to 3999.
Arabic → Roman
MMXXVI
Roman → Arabic
2026
Private & SecureRuns in your browser — nothing is uploaded
Easy to UseJust paste or type — instant results
Free ForeverUnlimited use, no sign-up
Fast & ReliableAdvanced tech, fast and stable
Roman numerals turn up on clock faces, book chapters, film credits and monuments, and reading a long one like MCMXCIV in your head is genuinely fiddly. Type an ordinary number to get the Roman form, or paste Roman numerals to get the plain number back.
How to use: Roman Numerals
- 1Enter inputType a number from 1 to 3999.
- 2Set optionsRead its Roman numeral.
- 3ProcessOr type a Roman numeral.
- 4Get resultRead the Arabic value.
Common use cases
Read a date in creditsDecode the Roman year at the end of a film or on a building's cornerstone.
Number a chapter or outlineGet the Roman numeral for a chapter, appendix or list level.
Check a tattoo or designConfirm a date converts to the Roman numerals you expect before it is set in ink or stone.
Learn the systemSee how a number breaks into thousands, hundreds, tens and units in Roman form.
Good to know
No zero, no decimalsRoman numerals only write whole counting numbers. Zero, negatives and fractions have no symbol, which is why the range starts at 1.
Capped at 3999Standard notation runs out at 3999, written MMMCMXCIX. Larger numbers need bars over letters, which this tool leaves out to stay readable.
Subtraction has rulesIV is four, not IIII, and IX is nine. A smaller symbol before a larger one subtracts, but only in set pairs, which the tool follows.
Watch for invalid inputStrings like IIII or VV are not valid Roman numerals. If a value will not convert, check it follows the standard form.