How to write 15 in Roman numerals
Roman numerals are built place by place, from the largest value to the smallest. For 15 the places are 10 (tens), 5 (ones).
- Write 10 as
X. - Write 5 as
V.
Joined together, X + V gives XV.
15 digit by digit
| Place | Value | Numeral | Rule used |
|---|---|---|---|
| tens | 10 | X | one symbol |
| ones | 5 | V | the five symbol on its own |
Check XV by reading it back
Reading XV from left to right and adding the pieces: X = 10, V = 5. Together that is 10 + 5 = 15, so XV and 15 match.
Mistakes to avoid with XV
- Only I, X and C may be placed before a larger symbol to subtract, so XV never contains forms such as VX or LC.
- Read XV 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 15
- 15 is an odd number and composite, with prime factors 3 x 5.
- In binary 15 is
1111and in hexadecimal it isF. - Written out, 15 is "fifteen".
- The digits of 15 add up to 6, so it is divisible by 3.
Where you will see 15 in Roman numerals
The number 15 appears as XV on milestone markers and in copyright dates for movies released in certain decades. Anniversary editions of products sometimes feature it too. Brands use these letters to evoke heritage and celebrate longevity without looking like a standard price tag or model number.
Numbers near 15
FAQ
What is 15 in Roman numerals?
15 is written XV in Roman numerals. It is built from X (10), V (5).
How do you write 15 in lowercase Roman numerals?
Lowercase Roman numerals use the same rules, so 15 is xv. 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
- 14 (XIV): previous page
- 16 (XVI): next page
- Roman numerals chart: the full list