Lumber Calculator
Calculate lumber for a batch of rectangular boards.
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What this tool does
Calculate lumber for a batch of rectangular boards. One board foot is 144 cubic inches. Actual dimensions are used.
How to use the Lumber Calculator
- Enter or select actual thickness in in.
- Enter or select actual width in in.
- Enter or select board length in ft.
- Enter or select board quantity.
- Read the calculated result; change any measurement to compare alternatives.
Formula
board feet = thickness(in) × width(in) × length(ft) × count / 12; cost = board feet × price
- thickness
- Actual thickness (in, before metric conversion)
- width
- Actual width (in, before metric conversion)
- length
- Board length (ft, before metric conversion)
- count
- Board quantity
One board foot is 144 cubic inches. Actual dimensions are used.
Worked example
For lumber calculator, the following measurements illustrate the exact method: Actual thickness: 1; Actual width: 6; Board length: 8; Board quantity: 10.
Inputs
- Actual thickness1 in
- Actual width6 in
- Board length8 ft
- Board quantity10
Result
- Total board feet40
- Total wood volume3.33 cu ft
Results explained
- Total board feet
- Total board feet from the formula above. One board foot is 144 cubic inches. Actual dimensions are used.
- Total wood volume
- Total wood volume from the formula above, expressed in cuft before metric conversion. One board foot is 144 cubic inches. Actual dimensions are used.
Frequently asked questions
Multiply inch thickness by inch width by foot length by quantity and divide by 12.
Use actual measured thickness and width unless your supplier explicitly prices on nominal rough dimensions. A nominal 2 × 4 is typically 1.5 × 3.5 inches after surfacing.
No unless a waste input is shown. Add stock for end trimming, defects and kerf rather than treating the computed total as a guaranteed cut plan.
Length inputs with a unit can be switched to metric; internal formulas keep a consistent inch/foot basis. Board foot outputs remain board feet.
Surfacing, moisture and the seller's pricing convention may change the billed volume.