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Roman Numeral

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Roman Numeral runs directly in the browser, so you can finish common tasks quickly without installing extra software.

Free to useBrowser-basedDirect shareable URL

Decimal → Roman

Roman → Decimal

Roman Numeral Rules

  • I, X, C can be repeated up to 3 times in a row.
  • V, L, D are never repeated.
  • Subtractive notation: IV=4, IX=9, XL=40, XC=90, CD=400, CM=900.
  • Valid range is 1 to 3999.

Reference Table

I
1
IV
4
V
5
IX
9
X
10
XL
40
L
50
XC
90
C
100
CD
400
D
500
CM
900
M
1000