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A board foot (BF) is a unit of volume used to measure and price hardwood lumber in the USA and Canada. One board foot equals a piece of wood 12 inches (30.48 cm) long, 12 inches (30.48 cm) wide, and 1 inch (2.54 cm) thick — or 144 cubic inches (2,360 cm³), which is 1/12 of a cubic foot.
Board footage measures volume, not area. Square footage only accounts for length and width. Board footage includes thickness, making it the standard measurement for pricing hardwood and softwood at sawmills and lumberyards across North America.
One board foot = 12 in × 12 in × 1 in = 144 cubic inches
Base volumetric unit for the hardwood lumber trade
12 board feet make up one full cubic foot of wood
Board footage accounts for thickness — square footage does not
To calculate board feet, measure the length in feet, the width in inches, and the thickness in inches, then multiply all 3 values together and divide by 12.
The board foot formula is:
Pay attention to the units. The length of the board is measured in feet. The width and thickness are measured in inches. Mixing up units produces wrong results.
Measure the board’s length in feet (ft). Divide inches by 12 to convert, if needed.
Measure the width in inches (in) at the widest usable point of the board.
Use the actual thickness in inches — a surfaced “1-inch” board is really 3/4 in (19 mm).
Length × Width × Thickness ÷ 12 — then multiply by the number of pieces.
Our board foot calculator applies this exact formula in real time. Type your board dimensions into the calculator above, select your preferred units (inches, feet, centimeters, meters, or mixed), and the tool outputs board feet per piece, total board footage, and estimated cost instantly. The live board diagram and formula visualizer update as you type each value.
💡 Use our flooring calculator and decking calculator for area-based coverage projects like decks and flooring.
The board foot formula is: Board Feet = Length (ft) × Width (in) × Thickness (in) ÷ 12.
There are 3 versions of the board foot formula based on which units you use:
| Formula Version | Equation | When to Use |
|---|---|---|
| Standard (mixed units) | L (ft) × W (in) × T (in) ÷ 12 | Length in feet, width and thickness in inches |
| All inches | L (in) × W (in) × T (in) ÷ 144 | All 3 dimensions measured in inches |
| All feet | L (ft) × W (ft) × T (ft) × 12 | All 3 dimensions measured in feet |
Visual representation of how each dimension feeds into the board foot formula
The division by 12 normalizes length (in feet) with width and thickness (in inches). Use the all-inches version (divide by 144) when every dimension is measured in inches.
There are 6 reasons this board foot calculator is the top choice for woodworkers, contractors, and lumber dealers:
Board footage and total cost update the moment you type — zero page reloads, zero waiting.
Uses the exact board foot formula trusted by sawmills and lumberyards, accurate to 2 decimal places.
Calculate board feet on any phone, tablet, or laptop right at the lumber yard or sawmill.
Enter price per board foot to get total project cost estimates for hardwood purchase optimization.
Works with feet, inches, millimeters, centimeters, meters, and mixed units like ft/in and m/cm.
Interactive 3D board diagram and formula visualizer update as you type each dimension.
There are 8 wood species commonly priced per board foot at lumberyards and sawmills in the USA and Canada:
| Wood Species | Type | Weight per BF | Typical Price Range (per BF) | Common Uses |
|---|---|---|---|---|
| Red Oak | Hardwood | 3.08–3.58 lb (1.40–1.62 kg) | $3.50–$6.00 | Furniture, flooring, cabinets |
| White Oak | Hardwood | 3.42–3.92 lb (1.55–1.78 kg) | $4.00–$7.50 | Outdoor furniture, barrels, flooring |
| Hard Maple | Hardwood | 3.25–3.75 lb (1.47–1.70 kg) | $4.00–$7.00 | Cutting boards, flooring, cabinets |
| Black Walnut | Hardwood | 2.50–3.17 lb (1.13–1.44 kg) | $7.00–$14.00 | Fine furniture, gunstocks, turning |
| Cherry | Hardwood | 2.75–3.17 lb (1.25–1.44 kg) | $4.50–$8.00 | Cabinets, millwork, furniture |
| Eastern White Pine | Softwood | 1.67–2.08 lb (0.76–0.94 kg) | $1.50–$3.50 | Trim, paneling, shelving |
| Douglas Fir | Softwood | 2.42–2.83 lb (1.10–1.28 kg) | $2.00–$4.50 | Framing, decking, structural beams |
| Yellow Poplar | Hardwood | 2.08–2.50 lb (0.94–1.13 kg) | $2.50–$4.50 | Paint-grade trim, custom millwork |
To calculate board feet for a real woodworking project, follow this 5-step example with 5 boards of white oak measuring 8 ft long, 10 in wide, and 1.25 in (5/4 rough-sawn) thick:
| Step | Value |
|---|---|
| Board Feet per piece | 8.33 BF |
| Total Board Feet (5 pieces) | 41.67 BF |
| Price per Board Foot | $4.15 |
| Total Cost | $172.93 |
💡 Add 10–15% extra board footage for waste from cuts, defects, and grain matching. Use our lumber waste calculator to estimate lumber costs with waste included.
To measure a board foot, follow these 5 steps:
Where to measure each dimension on a piece of lumber
The number of board feet in a 2×4 depends on the length of the board. A 2×4 is a piece of dimensional lumber with a nominal thickness of 2 inches (in) and a nominal width of 4 inches (in). The board foot formula for a 2×4 is: 2 × 4 × Length (ft) ÷ 12.
Here is a reference table for board feet in a 2×4 at 10 standard lengths from 6 ft to 24 ft:
| Length of 2×4 (ft) | Board Feet (BF) |
|---|---|
| 6 | 4 |
| 8 | 5.33 |
| 10 | 6.67 |
| 12 | 8 |
| 14 | 9.33 |
| 16 | 10.67 |
| 18 | 12 |
| 20 | 13.33 |
| 22 | 14.67 |
| 24 | 16 |
A 2×4×8 contains 5.33 board feet. The calculation uses nominal dimensions: 2 (in) × 4 (in) × 8 (ft) ÷ 12 = 5.33 BF. Using actual milled dimensions (1.5 in × 3.5 in × 8 ft), the result is 3.50 board feet. Lumberyards and sawmills in the USA and Canada price 2×4 dimensional lumber using nominal values, so 5.33 BF is the standard trade figure.
A board foot is a measure of volume, and a regular (linear) foot is a measure of length.
A board foot represents a piece of lumber 12 in × 12 in × 1 in, totaling 144 cubic inches (2,360 cm³). A linear foot is a straight-line distance of 12 inches (30.48 cm) with no width or thickness component.
| Measurement | Measures | Dimensions Used | Used For |
|---|---|---|---|
| Board Foot (BF) | Volume | Length × Width × Thickness | Hardwood lumber pricing, sawmill invoices, woodworking projects |
| Linear Foot (LF) | Length only | Length | Trim, molding, pipe, fencing |
| Square Foot (SF) | Area | Length × Width | Flooring, plywood sheets, walls, decking |
Board footage requires 3 dimensions. Linear footage uses 1 dimension. Square footage uses 2 dimensions. This is the main distinction between these lumber measurement units.
To convert board feet to square feet, divide the board feet by the thickness in inches:
This conversion works because board feet already account for thickness. Remove the thickness component, and the remaining value is the area in square feet.
For example, 20 board feet of 1-inch (2.54 cm) thick lumber = 20 ÷ 1 = 20 square feet of coverage. The same 20 board feet of 2-inch (5.08 cm) thick lumber = 20 ÷ 2 = 10 square feet.
This conversion is useful for flooring, wall paneling, and plywood projects where area coverage matters. Use our square feet to board feet calculator or plywood calculator for quick conversions. Board foot insulation for spray foam insulation follows the same volume concept — a 1 ft × 1 ft × 1 in slab equals 1 board foot.
To calculate board feet, multiply the length in feet by the width in inches by the thickness in inches, then divide by 12. The board foot formula is: Board Feet = Length (ft) × Width (in) × Thickness (in) ÷ 12. Measure the actual dimensions of the boards, plug the values in, and multiply by the number of pieces to get total board footage.
A board foot (BF) is a unit of volume equal to 144 cubic inches (2,360 cm³). One board foot represents a piece of lumber 12 inches long, 12 inches wide, and 1 inch thick. Sawmills, lumberyards, and hardwood dealers in the USA and Canada use board feet to price hardwood lumber, softwood, and dimensional lumber for woodworking projects, furniture building materials, and construction.
A 2×4×8 contains 5.33 board feet. The calculation uses nominal dimensions: 2 (in) × 4 (in) × 8 (ft) ÷ 12 = 5.33 BF. Using actual milled dimensions (1.5 in × 3.5 in), the result is 3.50 board feet. Lumberyards price 2×4 dimensional lumber using nominal values.
A board foot is a measure of volume, and a linear foot is a measure of length. A board foot uses 3 dimensions (length × width × thickness) and equals 144 cubic inches. A linear foot is a straight-line distance of 12 inches (30.48 cm) with no width or thickness. Board feet are used for lumber pricing. Linear feet are used for trim, molding, and fencing.
To calculate board feet in a log, use the Doyle rule or the International ¼-inch rule table. Measure the diameter of the shorter end of the log (not including bark) in inches and the length in feet. Use the Doyle formula: ((Diameter - 4) / 4)² × Length. For example, a log with a 12-inch diameter and 16-foot length contains approximately 64 board feet.
To convert board feet to square feet, divide the board feet by the thickness in inches: Square Feet = Board Feet ÷ Thickness (in). For example, 20 board feet of 1-inch (2.54 cm) thick lumber = 20 ÷ 1 = 20 square feet. This conversion is useful for flooring, wall paneling, and plywood projects.
Board foot insulation is a measurement of how much volume spray foam insulation can cover. A board foot of insulation equals 1 ft × 1 ft × 1 in (144 cubic inches), the same unit used for lumber. Estimate the square footage of the space, then multiply by the desired thickness in inches to find the total board feet of spray foam insulation needed.
A board foot of oak weighs between 3.08–4.67 lb (1.42–2.12 kg), with an average of 3.875 lb (1.77 kg). Red oak weighs 3.08–3.58 lb (1.40–1.62 kg) per board foot. White oak weighs 3.42–3.92 lb (1.55–1.78 kg) per board foot. Weight varies with density, variety, and growing location.
Dividing by 12 normalizes length (measured in feet) with width and thickness (measured in inches). The board foot formula uses mixed units: length in feet and width/thickness in inches. Dividing by 12 converts the result to the correct volume. Use the all-inches formula (divide by 144) when every dimension is measured in inches.
This calculator uses the exact industry-standard board foot formula, accurate to 2 decimal places. Real-world accuracy depends on measurement precision. Rough sawn lumber dimensions may differ from nominal sizes. Always measure actual thickness, width, and length for precise board footage and cost estimations.
This board foot calculator uses the industry-standard board foot formula. Actual lumber dimensions vary with milling, moisture content, and surfacing. Always measure boards yourself, add 10–15% waste, and confirm pricing with your lumber supplier. This tool is for informational and planning purposes only.
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