12 in Roman numerals at a glance
- Roman numeral
- XII
- Lowercase
- xii
- Letters
- 3
- Parts
- X · I · I
- Subtractive pairs
- None
- In words
- twelve
- Latin name
- duodecim
How XII is built
Roman numerals are written one decimal place at a time, from the largest place to the smallest. Converting each digit of 12 separately and joining the pieces gives XII:
| Place | Digit | Value | Numeral |
|---|---|---|---|
| Tens | 1 | 10 | X |
| Ones | 2 | 2 | II |
Reading it back, left to right:
- X = 10 → running total 10
- I = 1 → running total 11
- I = 1 → running total 12
The rules XII follows
- Largest to smallest. XII uses the symbols X and I (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 12 is a 4 or a 9, so XII is purely additive: just add the symbol values.
- Repetition. II repeats I 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 XII
- Clock and watch faces. XII marks the top of the dial (12 o’clock).
- The U.S. Constitution. Amendments are often cited in Roman numerals: Amendment XII set up separate electoral votes for president and vice president (ratified in 1804).
- Monarchs and popes. Regnal numbers use Roman numerals, as in Pope Pius XII, pope from 1939 to 1958.
- The modern Summer Games. They are officially numbered by Olympiad; the Games of the XII Olympiad belong to 1940: Tokyo, then Helsinki (cancelled because of World War II).
- Championship games. Pro football numbers its championship game with Roman numerals, starting from game I in January 1967. Game XII was played in early 1978.
- A single character. Unicode has a dedicated symbol for XII: Ⅻ (U+216B), mainly so East Asian text can set the numeral in one character cell. For ordinary writing, use the plain letters.
- Lists and outlines. Book chapters, acts of a play, outline headings and the preface pages of many books (in lowercase: xii) are numbered this way.
Numbers near 12 in Roman numerals
Frequently asked questions
How do you write 12 in Roman numerals?
12 is written XII. Break it into X (10), I (1), I (1) and add the parts: 10 + 1 + 1 = 12.
What is 12 in Latin?
The Latin cardinal number 12 is “duodecim.” The Romans wrote it as XII.
What is XII plus one?
XII + I = XIII (13). Adding one can change the whole ending of a numeral, which is why it helps to convert to digits, add, and convert back.