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9 in Roman Numerals

9 in Roman numerals is IX. It breaks down as IX, which adds up to 9.

  • Roman numeral
    IX
  • Lowercase
    ix
  • Breakdown
    IX
  • In words
    nine
  • Binary
    1001
  • Hexadecimal
    9

How to write 9 in Roman numerals

Roman numerals are built place by place, from the largest value to the smallest. For 9 the places are 9 (ones).

  1. Write 9 as IX.

Joined together, IX gives IX.

9 digit by digit

PlaceValueNumeralRule used
ones9IXsubtractive: one symbol before the ten symbol

Check IX by reading it back

Reading IX from left to right and adding the pieces: IX = 9. Together that is 9, so IX and 9 match.

Mistakes to avoid with IX

  • Do not write the 4s and 9s additively. 9 uses subtractive pairs (IX for 9), not strings like IIII or VIIII.
  • Only I, X and C may be placed before a larger symbol to subtract, so IX never contains forms such as VX or LC.
  • Read IX as one number, not letter by letter: add the values left to right, except where a smaller symbol sits before a larger one.

Facts about the number 9

  • 9 is an odd number and composite, with prime factors 32.
  • In binary 9 is 1001 and in hexadecimal it is 9.
  • Written out, 9 is "nine".
  • The digits of 9 add up to 9, so it is divisible by 3.
  • 9 is a perfect square (3 x 3).

Where you will see 9 in Roman numerals

Book prefaces often number their ninth page using IX for the number 9. Century names in historical texts also rely on this format. Historians and publishers retain it because Roman letters clearly distinguish broad time periods or introductory sections from specific dates and main chapter counts.

Numbers near 9

NumberRoman numeral
7VII
8VIII
9IX
10X
11XI

FAQ

What is 9 in Roman numerals?

9 is written IX in Roman numerals. It is built from IX (9).

How do you write 9 in lowercase Roman numerals?

Lowercase Roman numerals use the same rules, so 9 is ix. Lowercase is common for page numbers in a book's preface and for outline levels.

How do I convert any number to Roman numerals?

Split the number into thousands, hundreds, tens and ones, write each part with the symbols I, V, X, L, C, D and M, then join them from largest to smallest. Or paste it into the Roman numeral converter, which also converts back.

More roman numerals