Woodworking & Construction Calculators

Carpentry & framing

Lumber Board Foot & Cost Calculator (Inches, Feet, m³)

Use actual dressed or rough-sawn sizes, not nominal 2×4 labels. English pages default to inches, feet and board feet; German, Polish, Spanish and French pages default to millimetres and cubic metres. The unit toggle keeps the same physical stock while it recalculates volume and price.

Inputs

Units
in

Actual thickness, not the nominal size (a stamped 1×6 is typically ¾ in thick).

in

Actual width of each board.

ft

Length of each piece. Imperial uses feet; metric uses metres.

Number of identical boards.

%

Extra stock for defects, cuts and mismatch. Rough-sawn often needs 10–15%.

/BF

Price per board foot, or per cubic metre when Metric is selected.

Results

Net volume
40.000BF

Volume of the boards as entered, before waste.

Waste allowance
4.000BF
Volume to buy
44.000BF

Net volume plus waste.

Estimated cost
$198.00

Recommended gear

Calculation method

Board feet = (T × W × L × N) / 12, where T and W are actual inches, L is feet and N is piece count. One board foot equals 144 cubic inches, which is 12 in × 12 in × 1 in, or 0.002359737 m³. Metric volume is T_mm × W_mm × L_m × N / 1 000 000. Waste is a percentage of net volume. Estimated cost uses the unit price of the active unit system (per BF or per m³).

Exact formula

Board feet = (thickness in × width in × length ft × quantity) / 12. One board foot is 144 in³, or 0.002359737 m³. Cost = volume to buy × unit price. Waste is applied after net volume.

Board feet versus cubic metres

US yards quote rough lumber in board feet. European yards quote cubic metres. 1 m³ is about 423.776 board feet. This calculator stores one physical volume and shows it in the unit system you pick.

Price bases

If a yard sells by the board foot, stay in Imperial. If it sells by the cubic metre, switch to Metric so the unit price matches the quote. The toggle converts the price with the same 144 in³ board-foot definition.

Frequently asked questions

What is a board foot?

A board foot is a US lumber volume of 144 cubic inches — a piece 12 inches wide, 12 inches long and 1 inch thick. Ten 1×6×8 boards at actual 1 in × 6 in × 8 ft are 40 board feet before waste.

Should I enter nominal or actual size?

Enter the actual thickness and width you will receive. A stamped 2×4 is typically 1½ in × 3½ in. Using the stamp overstates volume and cost.

How does the Metric/Imperial toggle work?

Imperial uses inches, feet and board feet. Metric uses millimetres, metres and cubic metres. Switching units converts the same physical boards and the unit price, so cost stays consistent aside from rounding.

How much waste should I add?

S4S softwood often needs 5–10%. Rough-sawn or mixed lengths commonly need 10–15%. Figure extra if you have many short offcuts or a high defect rate.

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