Nominal vs Actual Lumber Sizes Explained
Board Foot Calculator
Board foot = thickness (in) × width (in) × length (ft) ÷ 12. Enter nominal sizes as billed, or switch to actual measured sizes.
Estimate only. Species prices vary by yard, region and date. Confirm the final tally and price with your lumber supplier before ordering.
Lumber is sold by nominal size, but the actual size after planing and drying is smaller. A nominal 2 x 4 is actually 1.5 x 3.5 inches. A nominal 1 x 6 is actually 0.75 x 5.5 inches.
How billing works
Softwood is normally billed at nominal size. Hardwood rough lumber is often tallied at rough thickness. This changes the board feet: billed nominal, a 2 x 4 x 8 ft board is 5.33 board feet; measured as actual wood, it is 2.92 board feet.
Worked example
Ten 2 x 4 x 8 ft boards billed nominal = 10 x 5.33 = 53.3 board feet. The same ten boards measured as actual wood = 10 x 2.92 = 29.2 board feet. The billing basis changes the total, so always compare quotes on the same basis.
FAQ
Is this price per board foot nominal or actual? Ask your yard, and use the same basis for every quote you compare.
Estimate only. Confirm with your supplier before ordering.