Lumber Calculator
Calculate lumber volume, board feet, total length, and cost for your construction projects
Calculate Lumber Requirements
The longest dimension of the lumber piece
The face width of the lumber
The smallest dimension (depth) of the lumber
Total number of lumber pieces needed
Lumber Calculations
Board Feet Formula: (Thickness × Width × Length) ÷ 144 (in inches)
Volume Formula: Length × Width × Thickness
One piece: 0.00 bf, 0.000 ft³
Cost Estimation
Example Calculation
2×4 Lumber Project
Lumber: 2×4 inch boards, 8 feet long
Dimensions: 8 ft × 4 in × 2 in
Quantity: 10 pieces
Actual dimensions: 1.5" × 3.5" × 8 ft (nominal vs actual)
Calculation
Board feet per piece = (2 × 4 × 8) ÷ 144 = 4.44 bf
Volume per piece = 8 × (4/12) × (2/12) = 0.444 ft³
Total for 10 pieces = 44.4 bf, 4.44 ft³
Result: 44.4 board feet, 80 linear feet
Common Lumber Sizes
2×4 (1.5" × 3.5")
Framing, studs, joists
Most common construction lumber
2×6 (1.5" × 5.5")
Floor joists, headers
Stronger than 2×4
1×4 (0.75" × 3.5")
Trim, paneling, shelving
Finishing work
Lumber Types
Lumber Tips
Nominal sizes differ from actual dimensions
Buy 10% extra for cuts and waste
Check lumber for warping and defects
Store lumber flat and dry
Understanding Lumber Measurements
Board Feet Calculation
Board feet is the standard measurement for lumber volume in North America. It represents the volume of a board that is 1 inch thick, 12 inches wide, and 12 inches long (144 cubic inches).
Formula
Board Feet = (Thickness × Width × Length) ÷ 144
Where dimensions are in inches
Why Board Feet?
- •Standard pricing unit for lumber
- •Easy comparison between different sizes
- •Industry standard for inventory
Nominal vs Actual Sizes
Lumber is sold by nominal dimensions, but actual dimensions are smaller due to drying and planing. Always use actual dimensions for precise calculations.
Common Conversions
2×4 Nominal
Actual: 1.5" × 3.5"
2×6 Nominal
Actual: 1.5" × 5.5"
1×6 Nominal
Actual: 0.75" × 5.5"
Note: This calculator uses the dimensions you enter exactly. Adjust for nominal vs actual sizes as needed.