Board feet calculator
Calculate board feet for dimensional lumber and hardwood. Enter thickness, width, length, and quantity to get the total board feet.
Lumber calculator
Choosing the Right Lumber
Lumber species, grade, and moisture content affect strength, appearance, and cost. Choose based on structural requirements, exposure to weather, and the final finish you want.
Softwood (Pine / Fir / Spruce): The most common framing lumber. SPF (Spruce-Pine-Fir) is affordable, readily available, and strong enough for most structural applications. Use #2 grade or better for framing. Suitable for walls, floors, roofs, and general construction.
Hardwood (Oak / Maple / Poplar): Denser and more decorative than softwood. Oak is extremely hard and wear-resistant, ideal for flooring, furniture, and visible beams. Maple is lighter in color and very hard. Poplar is a budget-friendly hardwood often used for painted trim.
Pressure-Treated Lumber: Softwood infused with preservatives for outdoor use. Resists rot, insects, and moisture. Required for all wood in contact with the ground or concrete. Used for decks, fences, posts, sill plates, and exterior framing.
Engineered Wood (LVL / Glulam / Plywood): Manufactured wood products with predictable strength and stability. LVL and glulam beams are stronger than solid wood of the same size. Plywood provides dimensional stability for sheathing, subfloors, and roof decks.
Lumber Type Cheat Sheet
Use this reference to select lumber for your project:
| Type | Best Used For | Strength |
|---|---|---|
| Softwood (SPF) | Framing, studs, joists, rafters, general construction | Good |
| Hardwood | Flooring, furniture, trim, visible beams, cabinetry | Very high |
| Pressure-Treated | Decks, fences, posts, sill plates, outdoor structures | Good (rot-resistant) |
| Engineered (LVL/Glulam) | Beams, headers, long spans, structural ridge boards | Excellent (predictable) |
Common lumber sizes
Nominal vs. actual lumber dimensions (actual is what the calculator uses):
- 2x4: 1.5 x 3.5 inches actual
- 2x6: 1.5 x 5.5 inches actual
- 2x8: 1.5 x 7.25 inches actual
- 2x10: 1.5 x 9.25 inches actual
- 4x4: 3.5 x 3.5 inches actual
- 1x6: 0.75 x 5.5 inches actual
Worked example
For example, for ten 2×6 boards, 8 ft long:
- Board feet = (2 × 6 × 8) ÷ 12 = 8 bd ft per board
- Total for 10 boards = 8 × 10 = 80 bd ft
- Actual dimensions: 1.5 × 5.5 in (nominal 2×6)
- Buy 11 boards to account for defects and offcuts
- Check each board for warping, twisting, or excessive knots before buying
Common mistakes
| Mistake | Why it matters |
|---|---|
| Confusing nominal vs actual dimensions | A 2×4 is actually 1.5 × 3.5 in — always use actual dimensions for calculations |
| Not accounting for waste | Plan for 10-15% waste from cutting, defects, and unusable sections |
| Buying pressure-treated for indoor use | PT lumber contains chemicals — use kiln-dried lumber for interior projects |