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Board Foot Calculator

Add every board in your project, pick the species, and get total board feet and lumber cost with a waste allowance. Prices per board foot come from the BuildersJig lumber library, last reviewed September 2026.

SpeciesThicknessWidth (in)LengthQtyBoard ft$ / bf · Cost
Net board feet0.00
Buy (with waste)0.00
Net cost$0.00
Cost with waste$0.00

Thickness under 1 inch is billed as 1 inch, the way a hardwood dealer does it. Prices are typical U.S. retail per board foot and vary by region, grade and width. Type your own price in any row to override it.

That was the lumber bill. Now build the piece.

BuildersJig is a 3D wood shop in your browser. Pull these same boards from the rack, mill them, cut them, join them, and walk out with dimensioned blueprints, a cut list and the cost, with kerf and waste tracked for you. Free plan, no credit card.

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The BuildersJig 3D workshop with boards on the bench

How to calculate board feet

A board foot is a volume: 144 cubic inches, the same as a board 1 inch thick, 12 inches wide and 12 inches long. Hardwood is sold this way because rough boards come in random widths and lengths, so a price per piece would mean nothing.

Board feet = thickness (in) × width (in) × length (ft) ÷ 12

If you measured the length in inches, divide by 144 instead of 12. Multiply by the number of identical boards.

Worked example

Six shelf boards, each 4/4 (1 inch) thick, 7.5 inches wide and 36 inches long: 1 × 7.5 × 36 ÷ 144 = 1.875 board feet each, 11.25 board feet for all six. In red oak at $6.10 per board foot that is $68.63. With a 20 percent waste allowance, buy 13.5 board feet and budget $82.35.

Quarter thickness chart

Hardwood thickness is quoted in quarters of an inch, measured rough. You pay for the rough size. After flattening and planing, expect to lose about 3/16 inch.

CalledRough thicknessTypical finishedCommon use
4/41"13/16"Cabinet parts, shelves, face frames, drawer fronts
5/41-1/4"1-1/16"Table tops, stair treads, thicker shelves
6/41-1/2"1-5/16"Chair parts, bed rails, bench tops
8/42"1-3/4"Table legs, workbench tops, thick slabs
12/43"2-3/4"Turning blanks, heavy legs, mantels

Lumber prices per board foot

These are the prices this calculator uses, from the same library the BuildersJig app prices your builds with. Last reviewed September 2026. Janka hardness is the force in pounds needed to embed a steel ball halfway into the wood. Higher is harder.

SpeciesTypePrice / board footJanka hardness
African MahoganyExotic$10.20830 lbf
AfromosiaExotic$19.001,450 lbf
American BeechHardwood$5.951,300 lbf
American ElmHardwood$4.00830 lbf
Bald CypressSoftwood$6.25510 lbf
BasswoodHardwood$4.75410 lbf
Black CherryHardwood$6.75950 lbf
Black WalnutHardwood$14.251,010 lbf
BloodwoodExotic$18.702,900 lbf
BocoteExotic$28.002,010 lbf
BubingaExotic$18.001,980 lbf
ButternutHardwood$9.35490 lbf
CherryHardwood$6.75
CocoboloExotic$82.002,960 lbf
Douglas FirSoftwood$4.50660 lbf
Eastern White PineSoftwood$4.50380 lbf
Ebony (Gaboon)Exotic$170.003,080 lbf
Hard MapleHardwood$7.001,450 lbf
HickoryHardwood$6.001,820 lbf
Indian RosewoodExotic$45.002,440 lbf
IpeExotic$11.503,510 lbf
JarrahExotic$9.001,910 lbf
JatobaExotic$11.602,350 lbf
KingwoodExotic$100.003,340 lbf
KoaExotic$60.001,170 lbf
LeopardwoodExotic$20.751,830 lbf
Lignum VitaeExotic$100.004,500 lbf
MerbauExotic$7.001,925 lbf
PadaukExotic$13.751,725 lbf
PecanHardwood$4.501,820 lbf
PineSoftwood$4.50
Pink IvoryExotic$90.003,230 lbf
Ponderosa PineSoftwood$4.50460 lbf
PoplarHardwood$4.20540 lbf
PurpleheartExotic$13.002,520 lbf
Red AlderHardwood$3.75590 lbf
Red OakHardwood$6.101,290 lbf
RedwoodSoftwood$7.25420 lbf
SapeleExotic$9.101,410 lbf
Sitka SpruceSoftwood$7.25510 lbf
Soft MapleHardwood$6.00950 lbf
Southern Yellow PineSoftwood$4.00690 lbf
Spanish CedarHardwood$12.00600 lbf
SycamoreHardwood$4.75770 lbf
TeakExotic$25.001,000 lbf
WengeExotic$19.001,930 lbf
Western Red CedarSoftwood$6.25350 lbf
White AshHardwood$4.501,320 lbf
White OakHardwood$8.951,360 lbf
Yellow BirchHardwood$4.951,260 lbf
YellowheartExotic$19.001,655 lbf
ZebrawoodExotic$25.001,575 lbf
ZiricoteExotic$45.052,020 lbf

How much waste should you allow?

Nobody gets 100 percent yield from rough lumber. The saw kerf takes 1/8 inch per cut, board ends are checked, planers snipe, and defects land exactly where you wanted a part. Use 15 to 20 percent for clear, straight stock, and 25 to 30 percent when you need to match grain or colour, or work around knots and sapwood. The most reliable way to know is to lay the parts out on the actual boards. That is what BuildersJig does: every cut is made on a real board in the 3D shop, and the offcuts and waste are counted for you.

Board foot questions

What is a board foot?

A board foot is a unit of volume for lumber: 144 cubic inches. Picture a board 1 inch thick, 12 inches wide and 12 inches long. Hardwood dealers price by the board foot because rough boards come in random widths and lengths.

What is the board foot formula?

Board feet = thickness (inches) × width (inches) × length (feet) ÷ 12. If the length is in inches, divide by 144 instead. Multiply by the number of boards for the total.

What does 4/4, 5/4, 6/4 or 8/4 mean?

Hardwood thickness is quoted in quarters of an inch, measured rough. 4/4 is 1 inch, 5/4 is 1.25 inches, 6/4 is 1.5 inches, 8/4 is 2 inches. You pay for the rough thickness even though the board finishes thinner after planing: 4/4 usually finishes at about 13/16 inch.

Do I use nominal or actual dimensions?

For hardwood sold by the board foot, use the rough (nominal) thickness, with any thickness under 1 inch counted as 1 inch, and the actual measured width and length. Construction lumber such as a 2x4 is sold by the piece or the linear foot, not the board foot.

How much extra lumber should I buy for waste?

Plan on 15 to 20 percent extra for clear, straight stock and 25 to 30 percent for boards with knots, sapwood or figure you need to match. Saw kerf, end checks, snipe and defects all take their share.

How do I convert board feet to cost?

Multiply total board feet by the price per board foot. For example, 12.5 board feet of walnut at $14.25 per board foot is $178.13 before tax and waste.