Hardwood lumber is sold by board footage, which is a standard way to measure volume.
Step 1: Measure your board
Thickness in inchesWidth in inchesLength in feet
Step 2: Use the board-foot formula
Board Feet = (Thickness × Width × Length) ÷ 12Example: A board that is 1″ thick × 8″ wide × 8′ long → (1 × 8 × 8) ÷ 12 = 5.33 board feet