Convert numbers to Roman numerals and Roman numerals to numbers, from 1 to 3999
Convert numbers to Roman numerals and Roman numerals to numbers instantly, in both directions at once: type in either field and the other updates by itself. It works from 1 to 3999 and checks that the Roman numeral is written correctly. It's useful for schoolwork, dates on monuments and in books, chapters, centuries, names of kings and popes, or tattoo designs.
The conversion is immediate in both directions:
To convert to a Roman numeral, type a number from 1 to 3999 in the first field.
To convert to a number, type the Roman numeral in the second field, in uppercase or lowercase.
The other field fills in instantly with the conversion.
Click Copy to use the result.
I = 1, V = 5, X = 10, L = 50, C = 100, D = 500 and M = 1000. All other numbers are formed by combining them.
A symbol to the right of a larger one adds (VI = 6); to the left it subtracts (IV = 4). Only I, X and C can subtract, and only from the next one or the one after: IV, IX, XL, XC, CD and CM.
A symbol is not repeated more than three times in a row: 4 is IV, not IIII. The tool warns you if the Roman numeral doesn't follow these rules.
They are still present in many contexts:
Centuries and dates: the 21st century (XXI) or the year MMXXVI on buildings and plaques.
Books and documents: chapters, volumes, appendices and front matter pages.
Names: kings, popes and events such as Elizabeth II, John XXIII or Super Bowl LVIII.
Design and tattoos: important dates written in Roman numerals.
Break the number down into thousands, hundreds, tens and ones: 1994 = M + CM + XC + IV = MCMXCIV.
Never repeat a symbol more than three times in a row.
V, L and D are never repeated or subtracted.
For tattoo dates, check the result twice: a mistake is hard to fix.
MMXXVI: MM (2000) + XX (20) + VI (6).
With the traditional symbols, the highest number that can be written without repeating M more than three times is 3999 (MMMCMXCIX). For larger numbers, a bar over the numeral was used to multiply it by a thousand.
No. The Roman system had no symbol for zero, which is why the conversion starts at 1.
The correct form is IV. IIII appears on some clocks by tradition, but it isn't considered valid.
Absolutely. All processing is done locally in your browser, so your text is never sent to any server. Your data remains completely private and secure.
There are no artificial limits imposed by our tool. The only limit is your browser's processing capacity, which can generally handle very large documents without problems.
No, all our text tools are completely free and require no registration, login, or provision of personal information.