Board Foot Calculator
Estimate the volume (and cost) of hardwood lumber in board feet.
This board foot calculator quickly estimates the volume of hardwood lumber you plan to buy and how much it will cost. A board foot measures volume, not area — it's the standard way to price rough lumber in the US and Canada.
What is a board foot?
Unlike square footage (which measures area), board footage measures volume. One board foot equals one square foot of lumber that is one inch thick.
1 board foot = 144 cubic inches = 1/12 cubic foot.
The math behind it
board feet = length (ft) × width (in) × thickness (in) ÷ 12
Watch the units: length is in feet, while width and thickness are in inches. Multiply by the number of boards for the total, then by the price per board foot for the cost.
Worked example
Five hardwood boards, each 8 ft long, 10 in wide and 1.25 in thick: per board = 8 × 10 × 1.25 ÷ 12 = 8.33 BF total = 5 × 8.33 = 41.67 BF At $4.15 / BF → cost = 41.67 × 4.15 = $172.92.
FAQ
How many board feet are in a 2x4?
A 2x4 is 2 in × 4 in. For an 8 ft length: 8 × 4 × 2 ÷ 12 = 5.33 BF. For 12 ft it's 8 BF, for 16 ft it's 10.67 BF.
Board foot vs linear foot — what's the difference?
A board foot is a measure of volume (width × length × thickness). A linear foot is simply 12 inches of length, ignoring width and thickness.
How much does a board foot of oak weigh?
About 3.08–4.67 lb (1.42–2.12 kg), averaging ~3.875 lb, because oak density ranges 37–56 lb/ft³.