1x4

1x4 is a dimension shorthand used in several fields to describe a rectangular piece or array that measures one unit by four units. Its precise meaning depends on the context.

In lumber and woodworking, 1x4 refers to a nominal board size. This is a 1-inch-thick, 4-inch-wide piece in its rough, unsurfaced form. After milling and planing, the actual dimensions are typically about 3/4 inch thick by 3 1/2 inches wide. Lengths vary, with common options such as 6, 8, 10, or 12 feet. The term is widely used for trim, casing, shelving, lightweight framing, and similar applications. Different species (pine, fir, poplar, etc.) and moisture content can affect color and strength but not the nominal label.

In mathematics and computing, a 1x4 matrix is a row vector with four elements, often written as [a b c d]. Its transpose is a 4x1 column vector. Such a matrix can be multiplied on the right by a 4xN matrix to yield a 1xN matrix, illustrating standard matrix multiplication rules. A 1x4 array can also represent a sequence or a set of four coordinates in one-dimensional space when used in software or data contexts.

Other uses include tile and panel sizing in construction and design, where 1x4 can describe units in inches. While the specific measurements differ by field, 1x4 generally denotes a one-by-four dimension, with nominal versus actual sizes the primary source of variation.