By any measurement, it’s no big deal to insert the inch symbol (") into a document on a Windows PC, on a Mac, or on iOS and Android devices. Follow any of the shortcuts below. The inch symbol is straight double prime marks, not “curly” or “smart” quotes. Learn how to type the inch symbol (″) using different methods, such as Alt code, HTML code, or keyboard shortcuts. Find out the meaning, category, and Unicode of this punctuation mark. The inch symbol (″) is a typographic character used to represent the inch, a unit of length in the imperial and US customary systems. The CSS code used to represent this inch is xxx33CC which can be obtained by copying and pasting on our website The inch (symbol: in or ″) is a unit of length in the British Imperial and the United States customary systems of measurement. It is equal to 25.4 mm and derived from the Roman uncia, meaning "one-twelfth".