Lumber Calculator
Calculate board feet, estimated cost, and total weight for your lumber order. Select a lumber size, wood species, and quantity to get instant estimates for framing, decking, fencing, and other projects.
25 studs for a typical wall section
Estimated Cost
$100 – $147
$0.75 – $1.10 per board foot
Total Board Feet
133.3 BF
Total Linear Feet
200 LF
Cost Per Piece
$4.00–$5.87
Total Weight
333 lbs
13.3 lbs/pc
SPF (Spruce-Pine-Fir): Most common framing lumber. Affordable and widely available at all home centers.
Actual Dimensions: A 2×4 is nominally 2" x 4" but actually measures 1.5" x 3.5" after drying and planing. Board feet are calculated using nominal dimensions (industry standard).
Not included: Delivery ($50-$150), fasteners (nails, screws, bolts), joist hangers, post brackets, waste/cutoff (order 10-15% extra), or sales tax.
Lumber Cost by Species (2026)
| Wood Species | Cost Per BF | Weight Per BF | Best For |
|---|---|---|---|
| SPF (Spruce-Pine-Fir) | $0.50–$0.80 | 2.5 lbs | Interior framing, studs |
| Douglas Fir | $0.70–$1.10 | 3.0 lbs | Beams, headers, structural |
| Pressure-Treated | $0.80–$1.30 | 3.5 lbs | Decks, ground contact, outdoor |
| Cedar | $1.20–$2.00 | 2.3 lbs | Fences, decks, siding |
*Prices as of February 2026. Lumber prices fluctuate with market conditions.
Nominal vs Actual Lumber Sizes
| Nominal Size | Actual Size | BF per 8ft |
|---|---|---|
| 2×4 | 1-1/2" × 3-1/2" | 5.33 |
| 2×6 | 1-1/2" × 5-1/2" | 8.0 |
| 2×8 | 1-1/2" × 7-1/4" | 10.67 |
| 2×10 | 1-1/2" × 9-1/4" | 13.33 |
| 2×12 | 1-1/2" × 11-1/4" | 16.0 |
| 4×4 | 3-1/2" × 3-1/2" | 10.67 |
*Board feet calculated using nominal dimensions (industry standard for pricing)
How We Calculate
A board foot (BF) is the standard unit for measuring and pricing dimensional lumber. One board foot equals a piece of wood 12" long, 12" wide, and 1" thick (144 cubic inches).
Board Feet = (Thickness" × Width" × Length') ÷ 12
Example: 2×8 × 12' = (2 × 8 × 12) ÷ 12 = 16.0 BF
Nominal vs Actual Dimensions
Lumber is sold by nominal size (2×4, 2×6, etc.) but the actual dimensions are smaller after drying and planing. A 2×4 measures 1.5" × 3.5" in reality. Board feet for pricing are calculated using nominal dimensions, which is the industry standard.
Cost Estimation
We multiply total board feet by the price-per-board-foot for each species. Prices reflect typical retail costs at Home Depot, Lowe's, and local lumber yards. Actual prices vary by region, grade, and market conditions.
Weight Estimation
Weight is calculated using average pounds per board foot for each species at typical moisture content. Pressure-treated lumber is heavier due to treatment chemicals and higher moisture content. Freshly treated lumber can be 50-75% heavier than kiln-dried wood.
Data Sources
Prices verified from Home Depot, Lowe's, local lumber yards, and building material suppliers (February 2026). Lumber prices are volatile and can change significantly with supply-chain and housing-market conditions.
Frequently Asked Questions
How do you calculate board feet for lumber? +
Board feet = (Thickness x Width x Length) / 12, where thickness and width are in inches and length is in feet. For example, a 2x4 that is 8 feet long = (2 x 4 x 8) / 12 = 5.33 board feet. Lumber yards use nominal dimensions for pricing.
How much does lumber cost in 2026? +
Lumber prices vary by species: SPF (Spruce-Pine-Fir) costs $0.50-$0.80 per board foot, Douglas Fir $0.70-$1.10/BF, Pressure-Treated $0.80-$1.30/BF, and Cedar $1.20-$2.00/BF. A standard 2x4x8 SPF stud costs $3-$6 at most home centers.
What is the difference between nominal and actual lumber sizes? +
Nominal size is the name (2x4) while actual size is the real measurement (1.5" x 3.5") after drying and planing. A 2x6 is actually 1.5" x 5.5", a 2x8 is 1.5" x 7.25", a 2x10 is 1.5" x 9.25", a 2x12 is 1.5" x 11.25", and a 4x4 is actually 3.5" x 3.5".
When should I use pressure-treated lumber? +
Pressure-treated lumber is required for any wood in ground contact or within 6 inches of the ground. This includes deck framing, fence posts, sill plates, and landscape timbers. It resists rot, insects, and moisture damage. Always use PT-rated for ground contact (UC4A or UC4B).
How many 2x4s do I need to frame a wall? +
For standard 16" on-center framing, you need approximately 1 stud per linear foot of wall, plus extras for corners, headers, and cripple studs. A 12-foot wall needs about 10-12 studs (8-foot), plus top and bottom plates (3 pieces at wall length each).
What is the weight of common lumber sizes? +
Weight varies by species. An 8-foot SPF 2x4 weighs about 10-13 lbs. An 8-foot pressure-treated 2x4 weighs about 17 lbs (heavier due to treatment chemicals and moisture). Cedar is lighter at about 9-11 lbs for an 8-foot 2x4. Douglas Fir falls in between at 12-15 lbs.
What is the difference between SPF, Douglas Fir, and Cedar lumber? +
SPF (Spruce-Pine-Fir) is the most affordable and common for interior framing. Douglas Fir is stronger and preferred for beams and structural applications. Cedar is naturally rot-resistant and best for outdoor projects like fences and decks. Pressure-treated SPF is the most economical choice for outdoor ground-contact uses.
How much extra lumber should I buy for waste? +
Buy 10-15% extra lumber to account for defects, warped boards, cutting waste, and mistakes. For complex projects with many angled cuts (like stairs or rafters), increase to 15-20%. Always inspect boards at the store and reject any that are severely warped, twisted, or cracked.
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