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Roman Numeral Converter.

Enter an Arabic number between 1 to 4,000,000



Roman Numeral Symbols

Symbol Value
I 1
V 5
X 10
L 50
C 100
D 500
M 1,000

How Roman Numbers Work

Roman Numerals read from left to right. Typically the largest number comes first, with smaller numbers following.

The following sequence reads 1 to 10 using addititive notation.

I, II, III, IIII, V, VI, VII, VIII, VIIII, X

While additive notation is used in some cases, Roman Numerals are commonly expressed using subtractive notation, where a person expresses 4 as 1 less than 5 [IV] instead of adding 1 four times [IIII]. The same expression is used for 9 as being 1 less than 10.

I, II, III, IV, V, VI, VII, VIII, IX, X

The pattern for expressing numbers by the power of 10 is the same.

X, XX, XXX, XL, L, LX, LXX, LXXX, XC, C

The pattern for expressing numbers by the power of 100 is also the same.

C, CC, CCC, CD, D, DC, DCC, DCCC, CM, M.

When a smaller number appears before a larger number it indicates subtractive notation applying to the symbol to the right.

874 = 800 + 70 + 4 = DCCC + LXX + IV = DCCCLXXIV.

If the number has a zero in it, that number is skipped.

409 = 400 + 9 = CD + IX = CDIX.

Writing Larger Numbers

  • Some Romans would use a vinculum above a Roman number to indicate the number is multiplied by 1,000.
  • Large numbers of 100,000 or more are expressed with a frame around them that is open at the bottom. This frame would indicate the portion of the number inside the frame be multiplied by 100,000.

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