Board Foot Calculator

Compute total board feet for any quantity of dimensional softwood or hardwood lumber — with a waste factor and optional cost estimate.

Lumber order

ft
%
Softwood: 10 %. Hardwood with defect cull: 15 – 20 %.
$

Calculation results

Total board feet

BF

Board feet per piece

BF

Total linear footage

ft

Softwood prices use nominal dimensions. For hardwood from a sawmill, enter rough cut sizes (4/4 = 1″, 5/4 = 1¼″, 8/4 = 2″).

Informational only. Board-foot conventions vary slightly by region. Confirm whether your supplier prices on nominal or actual dimensions before placing a large order.

What is a board foot?

A board foot (BF) is the standard unit for pricing dimensional and hardwood lumber in the U.S. and Canada. One BF is the volume of a board 1″ thick × 12″ wide × 1 ft long — exactly 144 in³ of lumber.

BFper piece = (Thicknessin × Widthin × Lengthft) ÷ 12
Total BF = BFper piece × pieces × (1 + waste / 100)

Worked example

Ten pieces of 2×6 × 12 ft pine, 10 % waste:

  • BF per piece = (2 × 6 × 12) ÷ 12 = 12 BF
  • Subtotal = 12 × 10 = 120 BF
  • With waste = 120 × 1.10 = 132 BF

At $1.20/BF (a typical SPF #2 price in 2026), the order is about $158 of lumber.

Nominal vs actual — which to enter

Softwood (SPF, Douglas Fir, Yellow Pine for framing): the industry prices by nominal dimensions. A 2×4 is calculated as 2 × 4, even though it actually measures 1½″ × 3½″ after surfacing.

Hardwood (oak, maple, walnut from a sawmill or specialty supplier): prices reflect the rough sawn dimension before surfacing. Enter actual rough sizes — 4/4 = 1″ thick rough, 5/4 = 1¼″, 8/4 = 2″. Width is variable; use the average width of the boards you are buying.

Common board-foot reference table

SizeBF per 8 ftBF per 10 ftBF per 12 ftBF per 16 ft
2×45.336.678.0010.67
2×68.0010.0012.0016.00
2×810.6713.3316.0021.33
2×1013.3316.6720.0026.67
2×1216.0020.0024.0032.00
4×410.6713.3316.0021.33
4/4 × 6″4.005.006.008.00
8/4 × 6″8.0010.0012.0016.00

Frequently asked questions

What is a board foot in lumber?
A board foot is a piece of lumber 1 inch thick, 12 inches wide and 1 foot long — exactly 144 cubic inches. It is the volume unit by which most dimensional and hardwood lumber is sold in the U.S. and Canada.
How do you calculate board feet?
Board feet per piece = (Thickness in inches × Width in inches × Length in feet) ÷ 12. Multiply by piece count and add a waste factor for the order total.
Should I use nominal or actual dimensions?
For softwood at a home centre or lumberyard, use nominal — that is the industry convention. For hardwood from a sawmill priced per BF, use the rough actual dimensions (4/4 = 1″, 5/4 = 1¼″, 8/4 = 2″).
How many board feet in a 2×4×8?
A 2×4 × 8 ft piece is (2 × 4 × 8) ÷ 12 = 5.33 BF. Ten of them is 53.3 BF before waste.
What is the difference between board feet and linear feet?
Board feet is a volume measurement (thickness × width × length). Linear feet is just the length. A 2×6 and a 2×12 of equal length have the same linear feet but very different board feet.
What waste factor should I use?
Straight cuts and standard joinery on softwood: 10 %. Hardwood with knot or defect cull: 15 %. Angled cuts, miters, or projects with lots of small parts: 15 – 20 %. Always round up to whole pieces or boards.
How does board-foot pricing work?
Suppliers post a price per BF. The lumberyard computes BF for each piece using the convention above and charges accordingly. Bundle pricing (e.g., 208 pieces of 2×4×8 per bundle) is typically 15 – 25 % cheaper per BF than loose retail.