Lumber Calculator
Find board feet, linear feet, and material cost for framing, decking, furniture, and fencing lumber.
Use nominal size for softwood pricing (a "2×4" = 2). Use actual (1.5) for hardwood by the board foot.
Your Lumber Estimate
- Enter board dimensions — thickness and width in inches, length in feet, for a single board.
- Use nominal for softwood — a "2×4" is entered as 2 and 4 — that is how suppliers price softwood board feet.
- Enter the quantity — the number of identical boards; the calculator totals board and linear feet.
- Add waste — 10% suits most straight-cut work; 15–20% for hardwood and pattern cuts.
- Add a price (optional) — enter price per board foot — framing pine runs about $0.80–$1.50/BF.
What Is a Board Foot?
A board foot (BF) is a unit of lumber volume: a piece 1 inch thick, 12 inches wide, and 1 foot long — 144 cubic inches. Hardwood at sawmills and specialty yards is priced by the board foot because boards come in random widths and lengths, so pricing by volume keeps comparisons fair. The formula is thickness (in) × width (in) × length (ft) ÷ 12.
Standard construction softwood — 2×4s, 2×6s, dimensional pieces — is usually sold by the piece or linear foot at home centers, but board footage still helps you compare cost across sizes and order from a yard that prices by volume.
Nominal vs Actual Lumber Dimensions
Every labeled size is larger than what you receive — mills surface lumber after cutting. This matters most for hardwood priced by actual board feet:
| Nominal | Actual | Board feet (8 ft) | Typical use |
|---|---|---|---|
| 1×4 | 3/4" × 3-1/2" | 1.75 BF | Trim, face frames, shelving |
| 1×6 | 3/4" × 5-1/2" | 2.75 BF | Siding, fence boards |
| 2×4 | 1-1/2" × 3-1/2" | 5.33 BF | Wall studs, blocking |
| 2×6 | 1-1/2" × 5-1/2" | 8.00 BF | Rafters, deck joists |
| 2×8 | 1-1/2" × 7-1/4" | 10.67 BF | Floor joists, stair stringers |
| 2×12 | 1-1/2" × 11-1/4" | 16.00 BF | Stringers, heavy headers |
| 4×4 | 3-1/2" × 3-1/2" | 10.67 BF | Posts, deck piers |
| 6×6 | 5-1/2" × 5-1/2" | 26.67 BF | Heavy posts, pergola columns |
Enter nominal dimensions when ordering from most suppliers — they calculate board feet the same way. Use actual dimensions only when a sawmill prices by physical volume.
Lumber Prices by Species (typical US ranges)
| Species | Type | Price per BF | Common uses |
|---|---|---|---|
| Douglas Fir / Pine | Softwood | $0.80–$1.50 | Framing, structural |
| Pressure-treated pine | Softwood | $1.25–$2.50 | Decking, ground contact |
| Cedar | Softwood | $2.00–$4.00 | Decking, siding, outdoor |
| Poplar | Hardwood | $3.00–$5.00 | Paint-grade cabinets |
| Red oak | Hardwood | $5.00–$8.00 | Flooring, stair treads |
| White oak | Hardwood | $6.00–$11.00 | Furniture, flooring |
| Black walnut | Hardwood | $10.00–$18.00 | Fine furniture, slabs |
Prices vary by region, grade, surface (rough vs S4S), and market. Always get a current quote from your supplier.
Board Foot Formulas
Use whichever unit your tape gives you:
Length in inches = BF = (Thickness" × Width" × Length") ÷ 144
Multiple boards = Total BF = BF per board × number of boards
With waste = Order qty = Total BF × (1 + waste %)
Material cost = Total cost = Order qty × price per BF
Use nominal dimensions for softwood framing (how suppliers price it) and actual surfaced dimensions for hardwood bought by volume.
Related Calculators
Board feet are the starting point for framing, decking, and woodworking — browse the full construction calculator collection.
Frequently Asked Questions
How many board feet in an 8-foot 2×4?
Using nominal dimensions: (2 × 4 × 8) ÷ 12 = 5.33 board feet. A 10-foot 2×4 is 6.67 BF and a 12-foot is exactly 8 BF. If a yard prices hardwood by actual size, use 1.5 × 3.5 instead, which drops the same board to 3.5 BF.
Board feet vs linear feet — what is the difference?
Linear feet measure length only; board feet measure volume, factoring in thickness and width. A 10-foot 2×4 and a 10-foot 2×6 are both 10 linear feet, but the 2×6 is 10 BF versus 6.67 BF for the 2×4. Use linear feet for trim, board feet for comparing cost across sizes.
Should I use nominal or actual dimensions?
Use nominal (2×4, 1×6) for softwood framing — that is how most suppliers price it. Use actual surfaced dimensions for hardwood from a sawmill where you pay for real volume. When unsure, ask which the supplier uses.
How much extra lumber should I order?
10% is standard for straight-cut framing. Use 15% for diagonal cuts and many openings, and 20% for hardwood where defect culling and grain matching add up. One returned board is cheaper than a second trip.
How many board feet are in a bundle?
A common bundle of 208 eight-foot 2×4s is about 1,109 board feet; 168 eight-foot 2×6s is roughly 1,344 BF. Bundle pricing at a yard usually runs 15–25% cheaper per board foot than home-center rack pricing.