Board Feet Calculator

Calculate how many board feet of lumber you are buying — and what it costs — for hardwood and rough lumber priced by the board foot.

How to use the Board Feet Calculator

Enter thickness and width in inches.
Enter length in feet and the number of boards.
Optionally enter the price per board foot.

How it works

A board foot is 144 cubic inches — a piece 1″ thick, 12″ wide and 12″ long. Board feet = thickness (in) × width (in) × length (ft) ÷ 12. Hardwood dealers use nominal (rough) thickness in quarters: 4/4 is 1″, 8/4 is 2″. An 8-foot 2x6 is 2 × 6 × 8 ÷ 12 = 8 board feet.

Board feet per 8-foot board

Board	Board feet
1x4	2.67
1x6	4
1x8	5.33
2x4	5.33
2x6	8
2x8	10.67
2x10	13.33
2x12	16
4x4	10.67

Frequently asked questions

How many board feet in a 2x4x8?

5.33 board feet.

What is 4/4 lumber?

1-inch-thick rough lumber (quarter-sawn thickness notation).

How do I calculate board feet in a log?

Use a log scale such as Doyle or International ¼-inch — they estimate usable lumber.

Why is hardwood sold by the board foot?

Hardwood comes in random widths and lengths, so volume is the fair measure.