板英尺计算器
板英尺（BF）是衡量木材体积的标准单位：1 板英尺等于一块 1 英寸厚、12 英寸宽、1 英尺长的木材。使用本计算器计算每块的板英尺数、多块木材的总板英尺数以及预估材料成本。选择规格木材预设（2×4、1×6 等）自动填充实际尺寸，或输入自定义尺寸。
Calculate Board Feet
Enter the dimensions of your lumber to calculate board feet. Use the nominal presets to auto-fill actual dimensions.
Related calculators:
常见问题
什么是板英尺？
板英尺（BF）是美国和加拿大木材体积的标准单位。一板英尺等于一块厚 1 英寸、宽 12 英寸、长 12 英寸的木料——相当于 144 立方英寸。板英尺由木材场、锯木厂和木工用来定价和计量木材。与线性英尺（仅长度）或平方英尺（仅面积）不同，板英尺包含三个维度：厚度、宽度和长度。
如何计算板英尺？
板英尺使用公式计算：板英尺 = (厚度（英寸）× 宽度（英寸）× 长度（英尺）) ÷ 12。例如，2 英寸厚、6 英寸宽、8 英尺长的木板包含 (2 × 6 × 8) ÷ 12 = 8 板英尺。若所有尺寸均以英寸计，则除以 144：(厚度 × 宽度 × 长度（英寸）) ÷ 144。对于多块木料，将每块的板英尺乘以块数。
木材的名义尺寸和实际尺寸有什么区别？
名义尺寸是用于标识木材的标注尺寸（如「2×4」、「1×6」），而实际尺寸是木材经干燥和加工后的真实尺寸。名义 2×4 实际测量为 1.5 英寸 × 3.5 英寸——各维度约小 25%。这种缩减发生在木材厂的窑干和表面刨平过程中。计算板英尺时，对精加工（刨光）木材使用实际尺寸，对毛锯木材使用名义尺寸。
2×4×8 木料有多少板英尺？
名义 2×4、长 8 英尺的木料，使用名义尺寸计算：(2 × 4 × 8) ÷ 12 = 5.33 板英尺。使用实际尺寸（1.5" × 3.5"）计算：(1.5 × 3.5 × 8) ÷ 12 = 3.5 板英尺。这一差异很重要：木材场通常以实际板英尺为硬木定价，而软木建筑木材通常按线性英尺或件销售，以固定价格而非按板英尺定价。
木材每板英尺的价格是多少？
每板英尺木材价格因树种、等级和市场条件差异很大。用于建筑的普通软木（松木、云杉、冷杉）每板英尺 $0.75-$2.00。用于露台的雪松和防腐处理松木每板英尺 $1.25-$5.00。流行硬木如橡木和枫木每板英尺 $4-$10。优质硬木如胡桃木和樱桃木每板英尺 $8-$20，柚木等热带木材可超过每板英尺 $40。
如何计算项目需要多少木材？
首先列出项目中每个木材部件的厚度、宽度、长度和数量。使用公式 (T × W × L) ÷ 12 计算每个部件的板英尺，然后乘以件数。将所有结果相加得到总板英尺。典型项目增加 10-15% 的废料系数，硬木项目因切割和配合更多可增加至 20%。大型项目应考虑额外增加材料以应对缺陷和测量误差。
能用板英尺计算木材成本吗？
可以。一旦知道项目的总板英尺，乘以每板英尺价格即可估算材料成本：总成本 = 总板英尺 × 每板英尺价格。例如，50 板英尺的红橡木以 $6.50/BF 计算，成本约为 $325。计算成本前请加入废料系数。另注意木材价格随市场条件波动——在确定预算前，请向供应商确认当前价格。
板英尺、线性英尺和平方英尺有什么区别？
线性英尺只测量长度（1 英尺 = 1 线性英尺），用于装饰线条、造型和简单的基于长度的定价。平方英尺测量面积（长度 × 宽度），用于地板、壁板和板材。板英尺测量体积（厚度 × 宽度 × 长度），用于木材定价。1 英寸厚木材的一板英尺覆盖 1 平方英尺；2 英寸厚木材每板英尺只有 0.5 平方英尺。板英尺是最完整的测量方式，因为它考虑了三个维度。
Understanding Board Feet
What is a Board Foot?
A board foot (BF or FBM — feet board measure) is the standard unit of volume for lumber in the United States and Canada. One board foot equals a piece of wood that is 1 inch thick, 12 inches wide, and 12 inches long — in other words, 144 cubic inches of wood.
Board feet are used by lumber yards, sawmills, and woodworkers to price and measure rough-cut and dimensional lumber. Unlike linear feet (which measure length only) or square feet (which measure area), board feet account for all three dimensions — thickness, width, and length — making them a true volumetric measure.
When buying lumber in bulk, suppliers price wood per board foot. Knowing how to calculate board feet lets you accurately estimate material costs for decks, furniture, cabinetry, framing, and any other woodworking or construction project.
Board Foot Formula
The board foot formula is straightforward. You need the thickness in inches, the width in inches, and the length in feet:
Primary Formula (length in feet):
Board Feet = (Thickness" × Width" × Length') ÷ 12
Alternative Formula (all dimensions in inches):
Board Feet = (Thickness" × Width" × Length") ÷ 144
Total for Multiple Pieces:
Total Board Feet = Board Feet per Piece × Number of Pieces
Worked Examples
Example 1: Standard 1×12 at 8 feet
A 1×12 board (actual 0.75″ × 11.25″) at 8 feet long:
(0.75 × 11.25 × 8) ÷ 12 = 67.5 ÷ 12 = 5.625 BF
Example 2: Ten 2×6 studs at 10 feet
A 2×6 (actual 1.5″ × 5.5″) at 10 feet, 10 pieces:
(1.5 × 5.5 × 10) ÷ 12 = 82.5 ÷ 12 = 6.875 BF each × 10 = 68.75 BF total
Example 3: Rough-sawn lumber 2″ × 8″ × 12 feet
Using nominal dimensions for rough-sawn stock:
(2 × 8 × 12) ÷ 12 = 192 ÷ 12 = 16 BF
Nominal vs Actual Dimensions
One of the most common sources of confusion in lumber purchasing is the difference between nominal and actualdimensions. When you buy a "2×4" from a lumber yard, it does not actually measure 2 inches by 4 inches.
Nominal sizes refer to the rough-cut green lumber dimensions before drying and surfacing. The drying process (kiln-drying) and surface planing reduce the wood's size. The result is that dressed (surfaced) lumber is consistently smaller than its nominal label.
For board foot calculations, you should use the actual dimensions when working with dressed lumber, and the nominal dimensions when working with rough-sawn lumber (which retains more of its original size).
| Nominal Size | Actual Thickness | Actual Width | Reduction |
|---|---|---|---|
| 1×4 | 0.75″ | 3.5″ | ~30% |
| 1×6 | 0.75″ | 5.5″ | ~31% |
| 1×8 | 0.75″ | 7.25″ | ~30% |
| 1×10 | 0.75″ | 9.25″ | ~31% |
| 1×12 | 0.75″ | 11.25″ | ~30% |
| 2×4 | 1.5″ | 3.5″ | ~31% |
| 2×6 | 1.5″ | 5.5″ | ~31% |
| 2×8 | 1.5″ | 7.25″ | ~30% |
| 2×10 | 1.5″ | 9.25″ | ~31% |
| 2×12 | 1.5″ | 11.25″ | ~30% |
| 4×4 | 3.5″ | 3.5″ | ~25% |
| 6×6 | 5.5″ | 5.5″ | ~17% |
Note: Rough-sawn lumber may be closer to nominal dimensions. Always measure your actual lumber before calculating for critical projects.
Common Lumber Sizes & Applications
Understanding which lumber sizes are standard for different applications helps you estimate materials more efficiently and avoid costly over- or under-ordering.
Framing Lumber
- 2×4 (1.5″ × 3.5″): Standard wall studs, spaced 16″ or 24″ on center. Most common framing member.
- 2×6 (1.5″ × 5.5″): Exterior walls for better insulation, floor joists for shorter spans.
- 2×8 (1.5″ × 7.25″): Floor joists, ceiling joists, rafters for medium spans.
- 2×10 (1.5″ × 9.25″): Floor joists and rafters for longer spans, stair stringers.
- 2×12 (1.5″ × 11.25″): Longer span floor joists, headers, stair stringers.
Decking & Outdoor
- 5/4×6 (1″ × 5.5″): Standard decking board, slightly thicker than 1×6 for better durability.
- 2×6: Decking for heavier loads or wider spacing between joists.
- 4×4 (3.5″ × 3.5″): Deck posts for standard-height decks up to about 6 feet.
- 6×6 (5.5″ × 5.5″): Deck posts for tall decks, pergola columns, heavy-duty applications.
Finish & Trim
- 1×4 (0.75″ × 3.5″): Baseboards, door casings, cabinet face frames, shelf cleats.
- 1×6 (0.75″ × 5.5″): Wide baseboard, wainscoting, cabinet sides, shelving.
- 1×8 (0.75″ × 7.25″): Wide shelving, furniture panels, drawer fronts.
- 1×10 & 1×12: Wide shelves, furniture tops, cabinet panels, stair treads.
Lumber Pricing Guide
Lumber prices fluctuate with market conditions, species, grade, and treatment. The following ranges reflect typical retail prices per board foot in the United States as of 2025–2026, and are intended as planning estimates only. Always get current quotes from your local lumber yard or home center.
| Species / Type | Typical $/BF | Common Uses |
|---|---|---|
| Construction Pine / SPF | $0.75 – $1.50 | Framing, sheathing |
| Douglas Fir | $1.00 – $2.00 | Framing, structural beams |
| Pressure-Treated Pine | $1.25 – $2.50 | Decks, ground contact |
| Cedar (Western Red) | $2.50 – $5.00 | Decking, fencing, siding |
| Poplar (Hardwood) | $2.00 – $4.00 | Furniture, cabinets (painted) |
| Oak (Red / White) | $4.00 – $8.00 | Furniture, flooring, cabinets |
| Maple (Hard) | $5.00 – $10.00 | Countertops, cutting boards, flooring |
| Cherry | $6.00 – $12.00 | Fine furniture, cabinets |
| Walnut | $8.00 – $20.00 | Premium furniture, gun stocks |
| White Ash | $4.00 – $8.00 | Tool handles, sports equipment, furniture |
| Teak | $20.00 – $40.00 | Marine, outdoor furniture, premium decking |
Grade matters: Select-grade (clear) lumber commands a significant premium over common or construction grades due to fewer knots and defects.
Bulk discounts: Buying full units or lifts from a sawmill or specialty supplier can reduce costs by 20–40% compared to retail home centers.
Waste factor: Add 10–15% to your board foot calculation to account for cuts, defects, and mistakes — especially for furniture and finish work where material quality is critical.