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Roman Numerals

Convert between numbers and Roman numerals instantly.

Roman numeral will appear here

Roman Numeral Reference

SymbolValueExample
I1III = 3
IV4IV = 4
V5VI = 6
IX9IX = 9
X10XIV = 14
XL40XL = 40
L50LX = 60
XC90XC = 90
C100CCC = 300
CD400CD = 400
D500DC = 600
CM900CM = 900
M1000MM = 2000

How Roman Numerals Work

Additive principle

Symbols are added left to right: VIII = 5+1+1+1 = 8

Subtractive principle

Smaller before larger means subtraction: IX = 10−1 = 9

Valid range

Standard Roman numerals cover 1 to 3999 (MMMCMXCIX)

No zero

Roman numerals have no symbol for zero — the concept came later

About the Roman Numeral Converter

The Roman Numeral Converter translates between ordinary numbers and Roman numerals in both directions — turning 2024 into MMXXIV and back — for dates, clock faces, book chapters, film credits, and monument inscriptions.

It follows the standard subtractive rules so the numerals are correctly formed, not just concatenated.

How to use it

  1. Enter a number or a Roman numeral.
  2. Read the converted value instantly.
  3. Copy the result.
  4. Switch direction to reverse it.

How it works

Converting to Roman numerals repeatedly subtracts the largest representable value and appends its symbol, applying the subtractive pairs (IV, IX, XL, XC, CD, CM) so the output is canonical. Converting from Roman numerals sums the symbol values while honouring those subtractive cases.

The tool validates input so malformed numerals are caught, and everything runs locally and instantly.

Worked example

Enter 2024 and you get MMXXIV; enter MCMLXXXIV and you get 1984 — handy for reading a cornerstone date or formatting a chapter heading.

Frequently asked questions

What range does it support?

The standard Roman numeral range, typically 1 to 3,999, using classical symbols.

Does it use subtractive notation?

Yes — it produces canonical forms like IV and IX rather than IIII.

Can it convert numerals back to numbers?

Yes — conversion works in both directions.

Is my input uploaded?

No — it runs in your browser.

Free and multilingual?

Yes — 25 languages, free.

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