Roofing & Framing

Board Foot Calculator

This board foot calculator works out board feet and lumber cost from thickness, width and length; see our deck construction guide for lumber choices. A board foot is a volume of wood 12 in × 12 in × 1 in (144 cubic inches). Hardwood, slabs and rough lumber are usually priced by the board foot, while dimensional softwood like 2×4s is usually sold per piece — but board feet are still useful to compare prices and estimate framing packages.

Results from this board foot calculator are planning estimates; confirm quantities and prices with your supplier or contractor before you order.

Your results will appear here

Enter your measurements and press Calculate. Defaults show a typical example.

How to use the board foot calculator

Enter thickness and width in inches.
Enter length in feet (and inches).
Enter the number of identical boards and, if you have it, the price per board foot.

Formula

Board feet = thickness (in) × width (in) × length (ft) ÷ 12. Equivalent: thickness × width × length (all inches) ÷ 144.

Worked example

An 8 ft 2×4: 2 × 4 × 8 ÷ 12 = 5.33 board feet. Ten 1×6 boards 10 ft long: 1 × 6 × 10 ÷ 12 × 10 = 50 BF.

Tips for using the board foot calculator

Use the nominal thickness for rough hardwood and actual sizes only when your supplier prices that way.
Add 15–20% for defects and offcuts when buying rough lumber for furniture or trim.
Compare price per board foot, not per board, when stores sell different lengths.
Rough-sawn boards shrink when planed, so buy thickness for the finished size you need; a 4/4 board usually planes to about 3/4 in, which matters for joinery and trim.