Why Are 2X4S Not Actually 2×4

In the past, when a timber was called a 2×4 [or “two-by-four”], it actually measured 2 inches by 4 inches. … Because of this extra milling, a 2×4 no longer measures a full 2 inches by four inches. Instead, a 2×4 is really only 1 1/2″ by 3 1/2″. The same is true of pine.

When did 2x4s stop being 2x4?

This pressured further compromise because thinner 2x4s were a way to compete in price with wood alternatives. Size standards, maximum moisture content, and nomenclature were agreed upon only as recently as 1964. The nominal 2×4 thus became the actual 1½ x 3½, imperceptibly, a fraction of an inch at a time.

What size is an actual 2x4?

The true measurement of a 2×4 is actually about 1.5×3. 5. When the board is first rough sawn from the log, it is a true 2×4, but the drying process and planning of the board reduce it to the finished 1.5×3. 5 size.