11 in Roman Numerals = XI
11 in Roman numerals is XI. It is ten plus one, with the I placed after the X so that it adds.
What is 11 in Roman numerals?
XI is X (10) + I (1), read left to right and added.
It starts the pattern that runs the length of the teens: take X for ten, then write the remainder after it. XI, XII, XIII, and then XIV where the tail becomes subtractive.
How XI is formed
Reading left to right, 11 breaks into these additive parts. Each Roman symbol is added in turn to reach the total.
X + I = 10 + 1 = 11.
Why 11 is written XI
Eleven is where people first meet a two-part numeral, and the order matters as much as it did with IV and VI. XI is eleven because the I follows the X; IX is nine because it precedes it. The same two characters, once again, carrying two different values.
Where 11 in Roman numerals is used
- Clock and watch dials: Eleven o'clock is XI, the last numeral before the XII at the top of the dial.
- Regnal names: Louis XI of France, who reigned from 1461 to 1483, is the standard example, and the numeral is read as the Eleventh.
- Chapters and appendices: Once a numbered list passes ten, Roman numerals start to get noticeably longer than their Arabic equivalents, and XI is where that becomes visible.
- Super Bowl XI: Played in January 1977, the first championship won by the Oakland Raiders.
Common mistakes writing 11 in Roman numerals
- IX is wrong. Same letters, reversed. IX is nine because the I comes first; eleven needs the X first.
Good to know about 11
- On a clock or watch face, 11 o'clock is shown as XI.
- Super Bowl XI was played in 1977; the NFL numbers its championship in Roman numerals (with the one-off exception of Super Bowl 50).
- 11 is a repdigit, the same digit repeated, which makes XI a tidy example of how each place value is written in turn.
Convert another number
11 is written XI in Roman numerals.
Frequently asked questions
How do you write 11 in Roman numerals?
Write 11 as XI, combining X + I. Start from the largest value that fits and work down until nothing is left over.
Is XI the 11 you see on a clock?
Yes. 11 o'clock is written XI on Roman-numeral clock and watch faces, with the one quirk that many dials print four as IIII rather than IV out of tradition.
Which Super Bowl is XI?
Super Bowl XI is the 11th Super Bowl, played in 1977. The NFL sets its championship number in Roman numerals, which is why so many people look up values like XI.
What number is XI?
XI is 11. Read the symbols left to right, treat any smaller-before-larger pair as a single subtraction, and add the groups together.
Related conversions
- 1100 in Roman numerals is MC, the same digit two place values up.
- 22 in Roman numerals is XXII, double 11.
- 12 in Roman numerals is XII, one more than 11.
- 10 in Roman numerals is X, one less than 11.