Calculate board feet, linear feet, number of pieces, and total cost for any lumber project. Build a custom material list for framing, decking, fencing, and woodworking.
Lumber is the backbone of residential construction — from framing walls and roofs to building decks, fences, and furniture. Accurate estimation prevents expensive waste and frustrating shortage-related delays. Whether you're a contractor preparing a material takeoff or a DIYer planning a weekend project, understanding how lumber is measured and priced is essential.
A board foot (bf) is the standard unit for measuring hardwood lumber volume. One board foot equals a piece 1 inch thick × 12 inches wide × 1 foot long (144 cubic inches). The formula uses nominal dimensions (the named size, not the smaller actual size).
This is one of the most confusing aspects of lumber for beginners. The nominal dimension is the name — what you ask for at the store. The actual dimension is what you physically receive, which is smaller due to milling and kiln-drying.
| Nominal | Actual | Board Ft/Lin Ft | Typical Price (8ft) |
|---|---|---|---|
| 2×4 | 1.5 × 3.5" | 0.667 | $3–$6 |
| 2×6 | 1.5 × 5.5" | 1.000 | $5–$9 |
| 2×8 | 1.5 × 7.25" | 1.333 | $8–$13 |
| 2×10 | 1.5 × 9.25" | 1.667 | $10–$18 |
| 2×12 | 1.5 × 11.25" | 2.000 | $14–$24 |
| 4×4 | 3.5 × 3.5" | 1.333 | $8–$15 |
| 1×6 | 0.75 × 5.5" | 0.500 | $3–$6 |
Standard wall framing uses 2×4 studs at 16 inches on center (O.C.). The quick formula: Wall Length (ft) × 0.75 + 1 = number of studs. Then add plates (double top plate + single bottom plate = 3 full-length boards per wall). For load-bearing walls, headers over doors and windows require 2×10 or 2×12 lumber, plus king studs and jack studs at each opening.
SPF (Spruce-Pine-Fir) is the most common framing lumber — it's straight, light, and affordable. Doug Fir is stronger and preferred for beams and headers. Pressure-treated (PT) lumber is chemically preserved for ground contact, outdoor structures, and moisture-prone areas. Cedar and Redwood are naturally rot-resistant and used for exterior applications where chemical treatment is undesirable.