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Roman numerals converter - Arabic to Roman and back, dates in Roman numerals

Type an Arabic number, a Roman numeral or a date - the converter shows the correct notation, breaks it into symbols and flags malformed numerals such as IIII or VX.

  • Free
  • No sign-up
  • Private
  • Runs locally

Range 1-3999. Larger numbers (up to 3,999,999) use a vinculum (overline).

Result

Roman numeral
MMXXVI

Breakdown into symbols: M = 1000 + M = 1000 + X = 10 + X = 10 + V = 5 + I = 1

Roman symbols

IVXLCDM
1510501005001,000

How to convert a number to Roman numerals

  1. 1.

    Choose a direction

    Arabic → Roman, Roman → Arabic or a date in Roman numerals.

  2. 2.

    Enter the number

    For example 2026 or MMXXVI. Letter case does not matter.

  3. 3.

    Read the result

    See the notation and its breakdown into symbols, then copy it.

  4. 4.

    Fix mistakes

    If a numeral is malformed (e.g. IIII), the converter suggests the correct one (IV).

Roman numeral symbols and rules

SymbolIVXLCDM
Value1510501005001000
  • Addition: symbols written from largest to smallest are added: VIII = 8, MDC = 1600.
  • Subtraction: only IV (4), IX (9), XL (40), XC (90), CD (400) and CM (900) are allowed.
  • Repetition: I, X, C and M may repeat up to three times; V, L and D never repeat. So 4 is IV, not IIII.
  • Only I, X and C can be subtracted, and only from the next two larger symbols - IC, IL, XM and VX are invalid.

Range and larger numbers

Standard notation covers 1-3999 (MMMCMXCIX). There is no zero. Larger numbers use a vinculum (a bar over the letters) that multiplies the value by 1000: 4000 = I̅V̅, 1,000,000 = M̅. The converter supports up to 3,999,999, including a bracket notation such as [IV] when an overline is inconvenient to type.

Dates: Roman numerals are most often used for the month (15.III.2024); a full Roman date is XV.III.MMXXIV.

Worked example and common values

To convert a number, split it into thousands, hundreds, tens and units, and write each part separately. 1994 = 1000 + 900 + 90 + 4 = M + CM + XC + IV = MCMXCIV. Going the other way, read left to right and subtract a symbol when it stands before a larger one: MCMXCIV = 1000 + (1000 − 100) + (100 − 10) + (5 − 1) = 1994.

NumberRomanWhere you see it
4 / 9IV / IXclock faces (often IIII), chapters
14XIVmonarchs (Louis XIV)
40XLSuper Bowl XL (2006)
99XCIXcommon error: IC is invalid
1999MCMXCIXfilm credits, building dates
2000MMcopyright years
2026MMXXVIcurrent year

For tattoos and engravings, double-check the date with the converter before committing - a missing I or a wrong subtraction (e.g. MIM for 1999) is a frequent and permanent mistake.

Frequently asked questions

How do I write 2026 in Roman numerals?

+
MMXXVI: MM = 2000, XX = 20, VI = 6.

Why is 4 written IV and not IIII?

+
Standard notation allows a symbol to repeat at most three times, and four is formed by subtraction (I before V). IIII appears on some clock faces but is considered non-standard.

What is the largest Roman numeral?

+
3999 (MMMCMXCIX) in standard notation. With a vinculum the converter goes up to 3,999,999.

How do I write 1999 in Roman numerals?

+
MCMXCIX (1000 + 900 + 90 + 9). The shortcut MIM is not valid in standard notation, because I may only be subtracted from V and X.

Is there a zero in Roman numerals?

+
No, the Roman system had no symbol for zero, so the converter starts at 1.

Updated: