How to write 17 in Roman numerals
Roman numerals are built place by place, from the largest value to the smallest. For 17 the places are 10 (tens), 7 (ones).
- Write 10 as
X. - Write 7 as
VII.
Joined together, X + VII gives XVII.
17 digit by digit
| Place | Value | Numeral | Rule used |
|---|---|---|---|
| tens | 10 | X | one symbol |
| ones | 7 | VII | the five symbol plus two |
Check XVII by reading it back
Reading XVII from left to right and adding the pieces: X = 10, VII = 7. Together that is 10 + 7 = 17, so XVII and 17 match.
Mistakes to avoid with XVII
- Never repeat a symbol more than three times in a row. When a fourth would be needed, the subtractive form takes over.
- Only I, X and C may be placed before a larger symbol to subtract, so XVII never contains forms such as VX or LC.
- Read XVII 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 17
- 17 is an odd number and a prime number.
- In binary 17 is
10001and in hexadecimal it is11. - Written out, 17 is "seventeen".
- The digits of 17 add up to 8.
Where you will see 17 in Roman numerals
The number 17 appears as XVII when labeling centuries in historical writing or formal documents. Authors prefer this Roman numeral style because it follows established typographic conventions that visually distinguish century designations from ordinary quantities or calendar years in the text.
Numbers near 17
FAQ
What is 17 in Roman numerals?
17 is written XVII in Roman numerals. It is built from X (10), VII (7).
How do you write 17 in lowercase Roman numerals?
Lowercase Roman numerals use the same rules, so 17 is xvii. 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
- 16 (XVI): previous page
- 18 (XVIII): next page
- Roman numerals chart: the full list