Estimate board feet, studs, and lumber costs for any project.
Common Lumber Sizes Reference
Understanding lumber sizes and board feet is essential for accurate ordering and cost estimation on any building project.
| Nominal | Actual | Board Ft per 8ft | Common Use |
|---|---|---|---|
| 2×4 | 1.5×3.5 in | 5.33 | Framing, studs |
| 2×6 | 1.5×5.5 in | 8.0 | Floor joists, rafters |
| 2×8 | 1.5×7.25 in | 10.67 | Headers, joists |
| 2×10 | 1.5×9.25 in | 13.33 | Floor joists, beams |
| 2×12 | 1.5×11.25 in | 16.0 | Ridge boards, headers |
Frequently Asked Questions
How do I calculate board feet?
Board feet = (thickness in inches × width in inches × length in feet) ÷ 12. A 1×12 board that is 8 feet long = (1×12×8)÷12 = 8 board feet. This is the standard lumber measurement unit.
What are actual vs nominal lumber sizes?
Nominal is the name (2×4), actual is the real dimension (1.5×3.5 inches). Lumber is named by its rough-cut size before drying and planing. A 2×6 is actually 1.5×5.5 inches, a 2×8 is 1.5×7.25 inches.
How much does lumber cost?
2×4×8: $3-8. 2×6×8: $5-12. 2×8×8: $7-15. 2×10×8: $10-20. 2×12×8: $12-30. Prices vary significantly by region, species (pine, fir, cedar), and market conditions.
What is pressure-treated lumber?
Pressure-treated wood has preservative chemicals forced deep into the fibers to resist rot, insects, and fungal decay. Required for ground contact, outdoor structures, and any wood exposed to moisture.
How many board feet in a 2×4?
A 2×4×8 ft board contains 5.33 board feet using nominal dimensions (2×4×8÷12). An 8-foot 2×6 contains 8 board feet. A 12-foot 2×4 contains 8 board feet.
What lumber is best for framing?
Douglas fir and southern yellow pine are the strongest and most common framing species. SPF (spruce-pine-fir) is widely available and affordable. Check grade stamps — #2 grade or better is standard for structural framing.
How do I calculate studs for a wall?
Divide wall length (in inches) by 16 (standard spacing) and add 1 for the end stud. Add extra studs for corners, intersections, and door/window king and jack studs. A 12-foot wall needs about 10-12 studs.
What is a linear foot vs a board foot?
A linear foot measures length only — a 10-foot 2×4 is 10 linear feet. A board foot measures volume — thickness × width × length ÷ 12. Linear feet is for purchasing; board feet is for calculating quantity.
How much waste should I plan for lumber?
Standard waste factor is 10-15%. Framing projects have less waste (cuts reuse). Finish carpentry has more waste (precision cuts). Complex projects or inexperienced builders should plan 15-20% waste.
What is the strongest wood for building?
For structural strength: Douglas fir, southern yellow pine, and white oak are the strongest common species. For framing, #2 grade Douglas fir provides the best strength-to-cost ratio.