Board foot calculator for lumber and timber

Multiply thickness in inches by width in inches by length in feet, then divide by 12. A 2 × 6 that is 8 ft long is 2 × 6 × 8 ÷ 12 = 8 board feet, so ten of them are 80. With all three sides in inches, divide by 144 instead: a board 1 × 12 × 12 in is exactly 1 board foot.

Nominal size for surfaced softwood: a 2 × 4 is counted as 2 × 4 in although it measures about 1½ × 3½ in. Hardwood is measured at its actual size, and rough hardwood thickness is given in quarters, 4/4 for 1 in and 8/4 for 2 in. With nominal sizing on, this calculator shows both: ten 2 × 6 × 8 ft are 80 BF nominal and 55 BF dressed.

1½ × 3½ in (38 × 89 mm) once dried and planed. Other 2× sizes lose ½ in of width up to 6 in and ¾ in above that: a 2 × 6 is 1½ × 5½, a 2 × 8 is 1½ × 7¼, a 2 × 10 is 1½ × 9¼ and a 2 × 12 is 1½ × 11¼ in. A nominal 1 in board is ¾ in thick, and a 4 × 4 is 3½ × 3½ in.

423.78. One board foot is 144 in³, exactly 2.359737216 litres, and 1 m³ ÷ 0.002359737216 m³ = 423.776. The metric example uses this: 20 pieces of 50 × 150 mm timber 3 m long are 0.45 m³, which is 190.70 board feet.

MBF means 1,000 board feet; MFBM and MBFT mean the same, and MMBF is a million board feet. A thousand board feet is 83.33 ft³, or 2.36 m³. A price of 600 per MBF is 0.60 per board foot, so an 8-board-foot 2 × 6 × 8 ft costs 4.80 at that rate.

정확도는 입력값과 계산 방법의 가정에 따라 달라집니다. 십진 연산은 유효숫자 50자리를 사용하지만, 추정값·수치해석 방법·원본 데이터의 정밀도는 더 낮을 수 있습니다. 표시값을 반올림해도 이러한 한계는 사라지지 않습니다. 독립적인 출처의 풀이와 대조한 계산 예시: 3. 예를 들어 “Ten 2 × 6 × 8 ft at 7.50 each”은 Hand calculation: 2 × 6 × 8 / 12 = 8 BF × 10 = 80; dressed 1.5 × 5.5 × 8 / 12 × 10 = 55 (PS 20 sizes)와 대조해 확인합니다.

USDA Forest Products Laboratory — Wood Handbook (FPL-GTR-282), lumber sizes and measurement; Board foot — 144 in³, exactly 2.359737216 L; NIST Voluntary Product Standard PS 20 — American Softwood Lumber Standard (dressed sizes).