What is the nominal length of wood?

The nominal length of wood refers to the standardized measurement used to describe lumber sizes before it is processed and finished. It is typically rounded to the nearest whole number, such as 2x4 or 2x6, but does not account for the actual dimensions after drying and planing, which are usually smaller. For example, a nominal 2x4 usually measures about 1.5 inches by 3.5 inches in actual size. The nominal length can also refer to the specified length of a board, often measured in feet or inches.