Board Foot Calculator

Add up board feet for up to three lumber sizes from thickness, width, length and piece count, plus waste, cubic feet, linear feet and cost per board foot.

Interactive calculator · Method BOARD-FOOT-1.0 · Last reviewed: 2026-11-04

Calculate your scenario

Board feet per row = thickness (in) × width (in) × length (ft) × pieces ÷ 12, because one board foot is 1 in × 12 in × 1 ft = 144 in³.

Your inputs

Try an example

Row 1 thickness (in)

Row 1 width (in)

Row 1 length (ft)

Row 1 pieces (pieces)

Row 2 thickness (in)

Row 2 width (in)

Row 2 length (ft)

Row 2 pieces (0 if unused) (pieces)

Row 3 thickness (in)

Row 3 width (in)

Row 3 length (ft)

Row 3 pieces (0 if unused) (pieces)

Waste and defect allowance (%)

Price per board foot (example) ($ per BF)

Default worked example. Edit the inputs to calculate your scenario.

Default worked example

Total board feet 106.6667 BF

Board feet with waste 117.3333 BF

Volume 8.8889 ft³ (0.2517 m³)

Linear feet 120 ft

Estimated cost $469.33

Σ (thickness in × width in × length ft × pieces ÷ 12) = 106.6667 BF; × 1.1 = 117.3333 BF × $4.00 = $469.33.

How to use the calculator

For each lumber size, enter thickness and width in inches, length in feet and the number of pieces. Leave unused rows at 0 pieces. Add a waste allowance and your price per board foot.

What the result means

Ten 2 × 6 × 8 ft boards are 80 BF and four 1 × 8 × 10 ft boards are 26.67 BF, 106.67 BF together; with 10% waste that is 117.33 BF, $469.33 at an example $4 per BF.

Formula and units

Board feet per row = thickness (in) × width (in) × length (ft) × pieces ÷ 12, because one board foot is 1 in × 12 in × 1 ft = 144 in³. Total = sum of rows; with waste = total × (1 + waste %). Cubic feet = board feet ÷ 12. Linear feet = Σ length × pieces. Cost = board feet with waste × price per board foot.

Worked examples

Ten 2 × 6 × 8 and four 1 × 8 × 10 at $4/BF: Row 1 thickness: 2 in; Row 1 width: 6 in; Row 1 length: 8 ft; Row 1 pieces: 10 pieces; Row 2 thickness: 1 in; Row 2 width: 8 in; Row 2 length: 10 ft; Row 2 pieces (0 if unused): 4 pieces; Row 3 thickness: 1 in; Row 3 width: 4 in; Row 3 length: 6 ft; Row 3 pieces (0 if unused): 0 pieces; Waste and defect allowance: 10 %; Price per board foot (example): 4 $ per BF.
Example result: Total board feet: 106.6667 BF; Board feet with waste: 117.3333 BF; Volume: 8.8889 ft³ (0.2517 m³); Linear feet: 120 ft; Estimated cost: $469.33.

Three hardwood sizes in actual dimensions at $6.50/BF: Row 1 thickness: 1.75 in; Row 1 width: 8 in; Row 1 length: 12 ft; Row 1 pieces: 6 pieces; Row 2 thickness: 0.75 in; Row 2 width: 5.5 in; Row 2 length: 8 ft; Row 2 pieces (0 if unused): 20 pieces; Row 3 thickness: 3.5 in; Row 3 width: 3.5 in; Row 3 length: 10 ft; Row 3 pieces (0 if unused): 2 pieces; Waste and defect allowance: 0 %; Price per board foot (example): 6.5 $ per BF.
Example result: Total board feet: 159.4167 BF; Board feet with waste: 159.4167 BF; Volume: 13.2847 ft³ (0.3762 m³); Linear feet: 252 ft; Estimated cost: $1,036.21.

Limitations and common mistakes

Enter the dimensions your supplier bills on. Some price on nominal sizes (a 2 × 6 counted as 2 in × 6 in), others on actual dressed or rough sizes, and the board-foot total changes accordingly; ask which one applies. Price and waste are your entries; defaults are examples. Kerf, planing loss and moisture shrinkage are covered only by the waste allowance.

Entering the length in inches in the feet field, which multiplies the board feet by 12.

Sources and assumptions

Method BOARD-FOOT-1.0; last formula review 2026-11-04. Sources and their supported claims. Calculation methodology.