20 in Roman numerals at a glance
- Roman numeral
- XX
- Lowercase
- xx
- Letters
- 2
- Parts
- X · X
- Subtractive pairs
- None
- In words
- twenty
- Latin name
- viginti
How XX is built
Roman numerals are written one decimal place at a time, from the largest place to the smallest. Converting each digit of 20 separately and joining the pieces gives XX:
| Place | Digit | Value | Numeral |
|---|---|---|---|
| Tens | 2 | 20 | XX |
| Ones | 0 | 0 | — (zero has no symbol) |
Reading it back, left to right:
- X = 10 → running total 10
- X = 10 → running total 20
The rules XX follows
- Largest to smallest. XX uses only the symbol X (2 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 20 is a 4 or a 9, so XX is purely additive: just add the symbol values.
- Repetition. XX repeats X two 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 XX
- The U.S. Constitution. Amendments are often cited in Roman numerals: Amendment XX moved the start of presidential and congressional terms to January (ratified in 1933).
- The modern Summer Games. They are officially numbered by Olympiad; the Games of the XX Olympiad belong to 1972: Munich.
- Championship games. Pro football numbers its championship game with Roman numerals, starting from game I in January 1967. Game XX was played in early 1986.
- Lists and outlines. Book chapters, acts of a play, outline headings and the preface pages of many books (in lowercase: xx) are numbered this way.
Numbers near 20 in Roman numerals
Frequently asked questions
How do you write 20 in Roman numerals?
20 is written XX. Break it into X (10), X (10) and add the parts: 10 + 10 = 20.
What is 20 in Latin?
The Latin cardinal number 20 is “viginti.” The Romans wrote it as XX.
What is XX plus one?
XX + I = XXI (21). Adding one can change the whole ending of a numeral, which is why it helps to convert to digits, add, and convert back.