Board Feet Calculator

Calculate board feet for hardwood and lumber. Enter the thickness and width in inches, the length in feet and the number of boards to get the total board feet and an optional cost estimate.

Board feet80 bd ft

Per board: 8 bd ft
Volume: 6.67 cu ft (0.189 m³)

How this calculator works

One board foot is a piece of wood 12 × 12 inches and 1 inch thick, or 144 cubic inches.

Board feet = thickness (in) × width (in) × length (ft) ÷ 12. Multiply by the number of boards for the total.

Hardwood dealers measure thickness in quarters: 4/4 is 1 inch, 6/4 is 1½ inches and 8/4 is 2 inches, measured rough before planing.

Example: ten 2 × 6 boards, 8 ft long

One board: 2 × 6 × 8 ÷ 12 = 8 board feet.
Ten boards: 8 × 10 = 80 board feet.
At $5 per board foot: 80 × 5 = $400.

Quick reference

Board feet per linear foot by board size
Board size	Board feet per foot
1 × 4	0.33
1 × 6	0.5
1 × 12	1
2 × 4	0.67
2 × 6	1
2 × 12	2

Board feet per linear foot by board size

Board size

Board feet per foot

1 × 4

0.33

1 × 6

0.5

1 × 12

2 × 4

0.67

2 × 6

2 × 12

Tips before you buy

Rough hardwood is sold by nominal (rough) thickness, so a planed 4/4 board finishes closer to ¾ inch.
Add 15–30% extra when buying rough lumber to allow for defects, knots and milling waste.
Construction lumber at home centers is usually priced per piece, not per board foot.

Frequently asked questions

How do you calculate board feet?

Multiply thickness in inches by width in inches by length in feet, then divide by 12. A 1 × 12 board that is 1 foot long is exactly 1 board foot.

How many board feet are in a 2×4×8?

A 2 × 4 that is 8 feet long contains 2 × 4 × 8 ÷ 12 = 5.33 board feet (using nominal dimensions).

Is a board foot the same as a linear foot?

No. A linear foot measures length only. A board foot is a volume, so it depends on the thickness and width of the board as well.