What is a board foot?

One board foot is a volume equal to 1 in × 12 in × 12 in. Lumber is often priced by this unit.

Should I use nominal or actual dimensions?

Follow your supplier’s billing. Hardwood is typically sold on nominal rough sizes, while softwood framing dimensions are often actual.

Does this include waste or defects?

No. Add extra board feet for knots, warp, and milling loss based on your project tolerance.

How do I handle random lengths?

Use an average length or run the math per length group and add the totals together.

How do I convert board feet to cubic feet?

Divide board feet by 12 to get cubic feet (since 1 BF = 1/12 cubic foot).

construction calculator

Board Foot Calculator

Calculate board feet per piece and total for lumber orders.

Results

Board feet per piece: 4.00
Total board feet: 40.00

How to use this calculator

Enter thickness and width in inches and length in feet.
Enter quantity of boards.
See board feet per piece and total board footage.

Inputs explained

Thickness: Board thickness in inches (use nominal or actual depending on your supplier).
Width: Board width in inches.
Length: Board length in feet.
Quantity: Number of pieces at the same dimensions.

How it works

Board feet per piece = (T × W × L) ÷ 12.

Multiply by quantity for the total order.

Formula

BF = (Thickness × Width × Length) ÷ 12

When to use it

Pricing hardwood purchases sold by the board foot.
Estimating framing material quantities for custom cuts.
Comparing yield when milling rough lumber to finished dimensions.

Tips & cautions

Hardwood board footage is usually based on rough, nominal sizes—confirm with your supplier whether surfaced sizes are used.
Include waste for knots, defects, and machining loss; this calculator shows net volume only.
For random lengths, calculate average length or run multiple scenarios and add them together.
Does not include waste, kerf, or defect allowances—add your own buffer.
Nominal vs actual dimensions can change totals; confirm what your yard bills on.
Assumes rectangular boards; live-edge or tapered pieces need a different approach.

Worked examples

1×6×8, qty 10

BF per piece = 4
Total = 40

2×10×12, qty 8

BF per piece = 20
Total = 160

Deep dive

This board foot calculator multiplies thickness, width, length, and quantity to show board feet per piece and total. Enter your lumber dimensions to price hardwood or framing orders.

Use it to compare suppliers, plan milling yield, and budget projects. Add your own waste factor for defects and saw kerf since board foot math itself is net volume.

FAQs

What is a board foot?: One board foot is a volume equal to 1 in × 12 in × 12 in. Lumber is often priced by this unit.
Should I use nominal or actual dimensions?: Follow your supplier’s billing. Hardwood is typically sold on nominal rough sizes, while softwood framing dimensions are often actual.
Does this include waste or defects?: No. Add extra board feet for knots, warp, and milling loss based on your project tolerance.
How do I handle random lengths?: Use an average length or run the math per length group and add the totals together.
How do I convert board feet to cubic feet?: Divide board feet by 12 to get cubic feet (since 1 BF = 1/12 cubic foot).

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Nominal vs actual sizes vary; adjust for surfaced lumber if needed.