30 in Roman numerals at a glance
- Roman numeral
- XXX
- Lowercase
- xxx
- Letters
- 3
- Parts
- X · X · X
- Subtractive pairs
- None
- In words
- thirty
- Latin name
- triginta
How XXX is built
Roman numerals are written one decimal place at a time, from the largest place to the smallest. Converting each digit of 30 separately and joining the pieces gives XXX:
| Place | Digit | Value | Numeral |
|---|---|---|---|
| Tens | 3 | 30 | XXX |
| Ones | 0 | 0 | — (zero has no symbol) |
Reading it back, left to right:
- X = 10 → running total 10
- X = 10 → running total 20
- X = 10 → running total 30
The rules XXX follows
- Largest to smallest. XXX uses only the symbol X (3 characters in all), and the values never increase from left to right except inside a subtractive pair.
- No subtraction needed. None of the digits of 30 is a 4 or a 9, so XXX is purely additive: just add the symbol values.
- Repetition. XXX repeats X three times. I, X, C and M may repeat up to three times in a row; V, L and D never repeat.
Where you will see XXX
- The modern Summer Games. They are officially numbered by Olympiad; the Games of the XXX Olympiad belong to 2012: London.
- Championship games. Pro football numbers its championship game with Roman numerals, starting from game I in January 1967. Game XXX was played in early 1996.
- Volumes and sequels. Book volumes, conference editions, film sequels and anniversary events often carry a Roman numeral; edition XXX would be the 30th.
Numbers near 30 in Roman numerals
Frequently asked questions
How do you write 30 in Roman numerals?
30 is written XXX. Break it into X (10), X (10), X (10) and add the parts: 10 + 10 + 10 = 30.
What is 30 in Latin?
The Latin cardinal number 30 is “triginta.” The Romans wrote it as XXX.
What is XXX plus one?
XXX + I = XXXI (31). Adding one can change the whole ending of a numeral, which is why it helps to convert to digits, add, and convert back.