Button sizes

The size of the button depends on its use. Shirt buttons are generally small, and spaced close together, whereas coat buttons are larger and spaced further apart. Buttons are commonly measured in lignes (also called lines and abbreviated L), with 40 lignes equal to 1 inch. For example, some standard sizes of buttons are 16 lignes (10.16 mm, standard button of men's shirts) and 32 lignes (20.32 mm, typical button on suit jackets).

The American National Button Society (NBS) has its own button sizing system which divides button sizes into 'small', 'medium' and 'large'.