Nominal vs Actual Size

Definition

Nominal size is the name stamped on the board. Actual size is the dressed section you receive. A stamped 2×4 is typically 1½ in × 3½ in; a stamped 1×6 is often about ¾ in thick. Entering the stamp overstates the physical volume. US yards, however, usually tally board feet on the nominal size (hardwood on the rough thickness, 4/4 = 1 in), so enter the sizes the yard tallies when you check a quote priced per board foot. Metric shops still need the mill’s finished millimetres, not the marketing name.

Calculators that use this

• Carpentry & framing

  Lumber Board Foot & Cost Calculator

  Convert actual lumber thickness, width, length and quantity into board feet or cubic metres, add waste, and estimate material cost in imperial or metric units.

• Carpentry & framing

  Wall Framing Stud Estimator

  Estimate studs, extra jack/king pairs for openings, and triple-plate lumber for a wall of given length and on-center spacing.