Lumber Board Foot (BF) & Cost Calculator
Calculate lumber board footage (BF), total cubic feet volume, linear footage, and hardwood pricing based on thickness (4/4, 8/4), width, and length.
Calculated Results
Frequently Asked Questions
What is a board foot in woodworking and lumber?
A board foot (BF or FBM) is a unit of volume measurement for rough hardwood lumber in the US and Canada. One board foot represents a piece of lumber 1 inch thick, 12 inches wide, and 12 inches long (144 cubic inches).
What is the formula to calculate board feet?
Formula using length in feet: Board Feet = (Thickness in inches × Width in inches × Length in feet) / 12. Formula using length in inches: Board Feet = (Thickness × Width × Length in inches) / 144.
What does the 'quarter' system (4/4, 8/4) mean in lumber?
Hardwood sawmills measure thickness in quarters of an inch: 4/4 ('four-quarter') is 1 inch thick rough; 5/4 is 1.25 inches thick; 8/4 is 2.0 inches thick. After surfacing/planing (S2S), a 4/4 board finishes to roughly 13/16" or 3/4" final thickness.
How does board foot differ from linear foot and square foot?
Linear footage measures only length. Square footage measures 2D surface area (length × width). Board footage measures true 3D physical volume (length × width × thickness).