15 in Roman numerals
15 is written XV. In chunks: X (10) + V (5) = 15.
The answer
XV
15 in Roman numerals is XV.
How XV is built
To write it, split 15 into 10 + 5. 10 is X, 5 is V, so 15 is X then V: XV.
To read it, XV has 2 chunks, and none of them is a take-away pair, so every chunk is added.
| Chunk | Worth | Why |
|---|---|---|
| X | 10 | Add |
| V | 5 | Add |
The mistake to watch for
Writing 15 as XIIIII
Wrong: XIIIII
XIIIII counts in ones, like a tally, and writes I more than three times in a row. Use V for five: 5 is V, which makes 15 XV.
Check it with the converter
Type XIIIII to see why XIIIII is not 15. The rule numbers it gives are the three rules on the Roman numerals page.
Converter set to XV (15).
Keep going
Questions parents ask
What is 15 in Roman numerals?
15 is XV.
What comes before and after XV?
14 is XIV and 16 is XVI.
Does XV use subtraction?
No. Every letter in XV is the same size as, or smaller than, the letter before it, so you just add them all.
What is the biggest letter in XV?
X, which is 10. XV has 2 letters.
Want to practise more?
Explore the diagnostic for more practice activities.