How Roman numerals work
Seven letters do all the work: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500 and M = 1,000. Write the values from largest to smallest and add them up: XVI = 10 + 5 + 1 = 16, and MDCCLXXVI = 1776.
A smaller numeral placed before a larger one is subtracted. Only six pairs are standard: IV (4), IX (9), XL (40), XC (90), CD (400) and CM (900). So 2026 is MMXXVI, 49 is XLIX (not IL), and 1999 is MCMXCIX. Without extra marks, the largest number you can write is MMMCMXCIX, which is 3,999.
Single-character numerals vs letters
The symbols on this page come from the Unicode Number Forms block. Ⅻ is one character that means 12, while XII is three ordinary letters. The one-character forms exist mainly for compatibility with East Asian character sets, where a numeral like Ⅻ has to fit into a single character cell, for example in vertical text.
For most writing, plain capital letters are the better choice: they work in every font and are easy to search and edit. Use the special characters when you want a compact look, such as Ⅻ in a watch face design or ⅲ as a list marker. Single characters only go up to Ⅻ, plus Ⅼ, Ⅽ, Ⅾ and Ⅿ, so 14 has to be written with two of them: ⅩⅣ.
In Word, you can type a code such as 216B and press Alt + X to get Ⅻ.
Where you still see them
Roman numerals name monarchs and popes (Charles III), movie sequels, and the Super Bowl (Super Bowl LX was played in 2026; Super Bowl 50 was the one game branded with regular digits). They also number book chapters, outline levels, copyright years in film credits and the hours on clock faces, where IIII is often used instead of IV.
For circled and boxed digits, see number symbols. To restyle the letters themselves, try the fancy text generator.