# Board foot calculator for lumber and timber

> Board foot calculator: board feet, linear feet, volume and cost for a stack of lumber, at nominal size and at the dressed size of a 2x4, 2x6 and more.

Интерактивная версия: https://www.calcopenly.com/ru/construction/board-foot-calculator
Тема: Калькуляторы строительства и дома

A board foot is 144 cubic inches of wood, a piece 1 in thick, 12 in wide and 1 ft long. Board feet for a stack are thickness (in) × width (in) × length (ft) ÷ 12 × pieces. Linear feet are length × pieces, and cost follows the basis the yard prices by: per piece, per board foot or per linear foot.

The default, ten 2 × 6 boards 8 ft long, is 80 board feet and 80 linear feet, costing 75.00 at 7.50 each. Softwood board feet are counted on the nominal size, but a dry 2 × 6 is dressed to 1½ × 5½ in, so the wood delivered is 55 board feet.

Turn off nominal sizing for rough-sawn hardwood or metric timber, which is measured as it is. Metric pieces convert at 1 board foot = 2.359737216 litres.

## Входные данные

- **Thickness**
- **Ширина**
- **Длина**
- **Pieces**
- **Sizes are nominal (a 2 × 6 is really 1½ × 5½ in)**: Lumber yards price softwood by nominal size; turn off for rough-sawn or metric timber measured as is.
- **Price is** (варианты: Per piece, Per board foot, Per linear foot)
- **Price**

## Результаты

- Борд-футы древесины (BF) — основной результат
- Board feet at dressed size (BF)
- Dressed size
- Linear feet (ft)
- Linear metres (m)
- Volume at the sizes entered (m³)
- Cost

## Формула

$$
\text{BF} = \frac{t_{\text{in}} \times w_{\text{in}} \times L_{\text{ft}}}{12} \times \text{pieces}
$$

## Примеры с решением

### Ten 2 × 6 × 8 ft at 7.50 each

- Thickness: 2 in
- Ширина: 6 in
- Длина: 8 ft
- Pieces: 10
- Price is: Per piece
- Price: 7.5
- **Борд-футы древесины: 80 BF**
- **Board feet at dressed size: 55 BF**
- **Linear feet: 80 ft**
- **Cost: 75.00**
- **Dressed size: 1.5 × 5.5 in**
- Источник проверки: Hand calculation: 2 × 6 × 8 / 12 = 8 BF × 10 = 80; dressed 1.5 × 5.5 × 8 / 12 × 10 = 55 (PS 20 sizes)

### Edge: 1 × 12 in × 1 ft is one board foot

- Thickness: 1 in
- Ширина: 12 in
- Длина: 1 ft
- Pieces: 1
- Price is: Per board foot
- Price: 4.5
- **Борд-футы древесины: 1 BF**
- **Board feet at dressed size: 0.7 BF**
- **Cost: 4.50**
- Источник проверки: Definition: 1 BF = 144 in³ = 1 in × 12 in × 12 in; dressed 0.75 × 11.25 × 12 / 144 = 0.703125

### Metric 50 × 150 mm × 3 m timber, 20 pieces, per linear foot

- Thickness: 50 mm
- Ширина: 150 mm
- Длина: 3 m
- Pieces: 20
- Sizes are nominal (a 2 × 6 is really 1½ × 5½ in): нет
- Price is: Per linear foot
- Price: 2
- **Борд-футы древесины: 190.7 BF**
- **Volume at the sizes entered: 0.45 m³**
- **Linear feet: 196.85 ft**
- **Cost: 393.70**
- Источник проверки: Python decimal: 0.05 × 0.15 × 3 × 20 = 0.45 m³ ÷ 0.002359737216 m³ per BF = 190.70; 60 m ÷ 0.3048 = 196.85 ft × 2

## Вопросы

### How do you calculate board feet?

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.

### Do you use nominal or actual size for board feet?

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.

### What are the actual dimensions of a 2x4?

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.

### How many board feet are in a cubic metre?

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.

### What does MBF mean in lumber pricing?

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.

### Насколько точен «Board foot calculator for lumber and timber»?

Точность зависит от введённых данных и допущений метода. Десятичная арифметика использует 50 значащих цифр, но оценки, численные методы и исходные данные могут быть менее точными; округление на экране не устраняет эти ограничения. Решённые примеры, проверенные по независимым источникам: 3. Например, «Ten 2 × 6 × 8 ft at 7.50 each» проверяется по источнику Hand calculation: 2 × 6 × 8 / 12 = 8 BF × 10 = 80; dressed 1.5 × 5.5 × 8 / 12 × 10 = 55 (PS 20 sizes).

### Откуда взята методика?

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).

## Источники

- [USDA Forest Products Laboratory — Wood Handbook (FPL-GTR-282), lumber sizes and measurement](https://research.fs.usda.gov/treesearch/62200)
- [Board foot — 144 in³, exactly 2.359737216 L](https://en.wikipedia.org/wiki/Board_foot)
- NIST Voluntary Product Standard PS 20 — American Softwood Lumber Standard (dressed sizes)