Board foot calculator: board feet, linear feet, volume and cost for a stack of lumber, at nominal size and at the dressed size of a 2x4, 2x6 and more.
By AdminDrafted with AI writing toolsUpdated Checked examples: 3
10 pieces of 2 × 6 in × 8 ft come to 80 board feet and 80 linear feet; the dressed wood is 55 BF.
One board foot is 144 in³: a piece 1 in thick, 12 in wide and 1 ft long.
Softwood is sold by nominal size; this is the wood you actually get.
A board foot is 144 cubic inches of wood, a piece 1 in thick, 12 in wide and 1 ft long. Board feet for a stack are thickness (in) × width (in) × length (ft) ÷ 12 × pieces. Linear feet are length × pieces, and cost follows the basis the yard prices by: per piece, per board foot or per linear foot.
The default, ten 2 × 6 boards 8 ft long, is 80 board feet and 80 linear feet, costing 75.00 at 7.50 each. Softwood board feet are counted on the nominal size, but a dry 2 × 6 is dressed to 1½ × 5½ in, so the wood delivered is 55 board feet.
Turn off nominal sizing for rough-sawn hardwood or metric timber, which is measured as it is. Metric pieces convert at 1 board foot = 2.359737216 litres.
Multiply thickness in inches by width in inches by length in feet, divide by 12, then multiply by the number of pieces. One board foot is 144 in³ of wood, a piece 1 in × 12 in × 1 ft. Ten 2 × 4s, 8 ft long, are 2 × 4 × 8 ÷ 12 = 5.33 BF each, or 53.33 board feet.
With every dimension in inches, divide by 144 instead: 2 × 6 × 96 ÷ 144 = 8. For metric timber, divide cubic meters by 0.002359737216, the exact volume of one board foot; a cubic meter is 423.78 board feet.
Board feet in each linear foot of nominal lumber:
Multiply by the total length to get the stack. Any size whose thickness × width is 12, such as a 2 × 6 or a 1 × 12, has as many board feet as linear feet.
Softwood is sold on its nominal size, but a dried and planed piece is smaller. Under the American Softwood Lumber Standard PS 20-25, a nominal 1 in board is ¾ in thick; 2 to 6 in dimensions dress ½ in smaller and 8 to 16 in dimensions ¾ in smaller.
Ten 2 × 6 × 8 ft pieces count as 80 board feet but measure 1½ × 5½ in, so they hold 55 board feet of wood, 68.75% of the nominal figure. Ten 2 × 4s hold 35 board feet against 53.33 nominal.
Hardwood and rough-sawn timber are measured at their actual size. Rough hardwood thickness is quoted in quarters of an inch: 4/4 is 1 in, 5/4 is 1¼ in and 8/4 is 2 in. A rough 4/4 board 8 in wide and 8 ft long is 5.33 board feet.
Lumber yards quote per piece, per board foot or per linear foot, and the same stack costs different amounts on each. Match the basis to the quote before comparing suppliers.
To use a price per thousand board feet (MBF), divide it by 1,000: 600 per MBF is 0.60 per board foot, so the 80 board feet above cost 48.00. One MBF is 83.33 ft³, or 2.36 m³.
"Default" is ten nominal 2 × 6 × 8 ft pieces at 7.50 each. "One board foot" is a single 1 × 12 in piece 1 ft long at 4.50 per board foot. "Board foot pricing" prices the ten 2 × 6s at 0.60 per board foot.
"Actual dimensions" enters the same ten pieces at their dressed 1.5 × 5.5 in, still at 7.50 each. "Metric timber" is twenty 50 × 150 mm pieces, 3 m long, at 2.00 per linear foot: 0.45 m³ and 60 m of timber.
| Scenario | Board feet at entered sizes | Linear feet | Cost |
|---|---|---|---|
| Default | 80.000000 | 80.000000 | 75.000000 |
| One board foot | 1.000000 | 1.000000 | 4.500000 |
| Board foot pricing | 80.000000 | 80.000000 | 48.000000 |
| Actual dimensions | 55.000000 | 80.000000 | 75.000000 |
| Metric timber | 190.699200 | 196.850394 | 393.700787 |
To count the boards a project needs before totaling them here, use the deck calculator or the fence calculator.
Checked against: Hand calculation: 2 × 6 × 8 / 12 = 8 BF × 10 = 80; dressed 1.5 × 5.5 × 8 / 12 × 10 = 55 (PS 20 sizes)
Checked against: Definition: 1 BF = 144 in³ = 1 in × 12 in × 12 in; dressed 0.75 × 11.25 × 12 / 144 = 0.703125
Checked against: 0.05 × 0.15 × 3 × 20 = 0.45 m³ ÷ 0.002359737216 m³ per BF = 190.70; 60 m ÷ 0.3048 = 196.85 ft × 2
Multiply thickness in inches by width in inches by length in feet, then divide by 12. A 2 × 6 that is 8 ft long is 2 × 6 × 8 ÷ 12 = 8 board feet, so ten of them are 80. With all three sides in inches, divide by 144 instead: a board 1 × 12 × 12 in is exactly 1 board foot.
Nominal size for surfaced softwood: a 2 × 4 is counted as 2 × 4 in although it measures about 1½ × 3½ in. Hardwood is measured at its actual size, and rough hardwood thickness is given in quarters, 4/4 for 1 in and 8/4 for 2 in. With nominal sizing on, this calculator shows both: ten 2 × 6 × 8 ft are 80 BF nominal and 55 BF dressed.
1½ × 3½ in (38 × 89 mm) once dried and planed. Other 2× sizes lose ½ in of width up to 6 in and ¾ in above that: a 2 × 6 is 1½ × 5½, a 2 × 8 is 1½ × 7¼, a 2 × 10 is 1½ × 9¼ and a 2 × 12 is 1½ × 11¼ in. A nominal 1 in board is ¾ in thick, and a 4 × 4 is 3½ × 3½ in.
423.78. One board foot is 144 in³, exactly 2.359737216 litres, and 1 m³ ÷ 0.002359737216 m³ = 423.776. The metric example uses this: 20 pieces of 50 × 150 mm timber 3 m long are 0.45 m³, which is 190.70 board feet.
MBF means 1,000 board feet; MFBM and MBFT mean the same, and MMBF is a million board feet. A thousand board feet is 83.33 ft³, or 2.36 m³. A price of 600 per MBF is 0.60 per board foot, so an 8-board-foot 2 × 6 × 8 ft costs 4.80 at that rate.
This calculator includes 3 worked examples with independently sourced answers. They run in the test suite, and you can run them here too.