How Many Board Feet of Lumber Do You Need?
Pick a lumber size or enter dimensions — instantly get board feet and cost.
Last updated: April 26, 2026
Enter Lumber Details
Most common framing lumber
Quick tip: Lumber presets use nominal dimensions (industry standard). For rough or specialty lumber, select 'Custom Size' and enter actual dimensions.
Using 4/4 notation (hardwood)
Add Cost Estimate (optional)
Softwood framing: $2-4/BF. Hardwood: $4-12/BF depending on species.
Results
Board Feet per Piece
5.333
4" × 2" × 8 ft
Total Board Feet
53.33
10 pieces
BF per Linear Foot
0.667
Actual Thickness
2"
Formula: Width(in) × Thickness(in) × Length(ft) ÷ 12 = Board Feet. NHLA rule: length rounds down to nearest whole foot.
Worked Examples
Deck Framing
20 pieces 2×8 × 12 ft
320 board feet total
Workbench Top
4 pieces 2×12 × 6 ft
48 board feet
Hardwood Table
6/4 hardwood × 10" wide × 8 ft
10 board feet per piece
Board Feet per Linear Foot Guide
Quick reference: how many board feet in 1 foot of common lumber sizes.
| Nominal Size | Dimensions (for BF calc) | BF per Linear Foot |
|---|---|---|
| 2×4 | 2" × 4" | 0.667 |
| 2×6 | 2" × 6" | 1.0 |
| 2×8 | 2" × 8" | 1.333 |
| 2×10 | 2" × 10" | 1.667 |
| 2×12 | 2" × 12" | 2.0 |
| 4×4 | 4" × 4" | 1.333 |
| 4×6 | 4" × 6" | 2.0 |
| 4×8 | 4" × 8" | 2.667 |
| 1×4 | 1" × 4" | 0.333 |
| 1×6 | 1" × 6" | 0.5 |
| 1×8 | 1" × 8" | 0.667 |
| 1×10 | 1" × 10" | 0.833 |
| 1×12 | 1" × 12" | 1.0 |
Frequently Asked Questions
A board foot (BF) is a volume measure for lumber: 1 inch thick × 12 inches wide × 1 foot long, or 144 cubic inches. It's the standard unit for buying hardwood and some softwood lumber at lumber yards.
Formula: Board Feet = Width(inches) × Thickness(inches) × Length(feet) ÷ 12. For softwood (2×4, 2×6), use nominal dimensions. For hardwood, use actual thickness. Our calculator handles this automatically.
Industry standard: softwood dimensional lumber is calculated using nominal sizes. A '2×4' is calculated as 2" × 4" (nominal) = 0.667 BF/ft, not the actual 1.5" × 3.5". This matches lumber yard pricing conventions.
Hardwood thickness measured in quarters of an inch. 4/4 = 1" thick, 6/4 = 1.5" thick, 8/4 = 2" thick. This notation gives ACTUAL thickness, not nominal. Enable '4/4 notation' checkbox for hardwood.
A 2×4 (nominal 2" × 4") has 0.667 board feet per linear foot. An 8-foot 2×4 = 5.33 board feet. A 10-foot 2×4 = 6.67 board feet. Select '2×4' preset and enter your length for instant calculation.
Use 'Custom Size' when buying rough lumber, specialty sizes, or when the lumber yard quotes actual dimensions. Enter the exact width and thickness in inches for accurate board feet.