Home Calculators Construction Lumber Calculator

Lumber Calculator

Calculate board feet, linear feet, and material costs for wood projects. Perfect for framing, decking, furniture, and construction projects.

Calculate Lumber Requirements

Select calculation type and enter dimensions to estimate lumber needed.

Board Feet Calculator

Calculate board feet for individual pieces of lumber.

Common lengths: 8, 10, 12, 16 feet

Linear Feet Calculator

Calculate total linear feet needed for multiple pieces.

Leave 0 for no spacing

Project Estimate

Estimate lumber for common projects like decks and framing.

Lumber Calculation Results

Total Required
Based on your inputs
-
Board Feet
-
Linear Feet
-
Number of Boards
-
Estimated Cost
-

Material Breakdown

Purchasing Tips

  • Order 10-15% extra for waste and defects
  • Check for straight boards without excessive warping
  • Pressure-treated lumber for outdoor projects
  • Consider delivery costs for large orders

Lumber Tips

  • 📏

    Actual vs Nominal

    A 2×4 actually measures 1.5" × 3.5". Account for this in calculations.

  • 🌧️

    Moisture Content

    Store lumber flat and allow to acclimate to local humidity before use.

  • 🔨

    Fastener Spacing

    Space nails/screws every 16" for framing, 6-8" for decking.

  • 🛡️

    Wood Treatment

    Use pressure-treated wood for ground contact and outdoor projects.

Related Calculators

Common Lumber Sizes

Nominal Actual Board Ft/ft
2×4 1.5" × 3.5" 0.667
2×6 1.5" × 5.5" 1.000
2×8 1.5" × 7.25" 1.333
2×10 1.5" × 9.25" 1.667
2×12 1.5" × 11.25" 2.000

Complete Guide to Lumber Calculations

Accurate lumber calculation is essential for any woodworking or construction project. Understanding board feet, linear feet, and material requirements helps prevent waste and ensures you purchase the right amount of lumber.

Understanding Board Feet

A board foot is a volume measurement used in the lumber industry. One board foot equals 144 cubic inches (12" × 12" × 1").

Board Feet Formula:

Board Feet = (Thickness(in) × Width(in) × Length(ft)) ÷ 12

Example: A 2×6 that's 8 feet long:

(1.5" × 5.5" × 8') ÷ 12 = 66 ÷ 12 = 5.5 board feet

Common Lumber Dimensions

Nominal Size Actual Size (inches) Board Feet per Linear Foot Common Uses
1×4 0.75 × 3.5 0.292 Trim, shelving
2×4 1.5 × 3.5 0.667 Wall framing, studs
2×6 1.5 × 5.5 1.000 Floor joists, headers
2×8 1.5 × 7.25 1.333 Rafters, beams
2×10 1.5 × 9.25 1.667 Floor joists, beams
2×12 1.5 × 11.25 2.000 Beams, headers

Lumber Estimating Guidelines

🏠 Wall Framing

Studs: 16" on center = ~1.33 studs per linear foot

Plates: 2 top plates, 1 bottom plate per wall

Example: 20' wall needs ~27 studs + plates

🛋️ Deck Construction

Decking: 5.5" wide boards = ~2.2 boards per foot width

Joists: 16" on center = ~0.75 joists per foot length

Example: 12×20 deck needs ~53 decking boards

🌳 Fence Building

Posts: 8' on center = posts = length ÷ 8 + 1

Rails: 2-3 rails between posts

Pickets: 5.5" pickets = ~2.2 pickets per foot

Frequently Asked Questions

What's the difference between board feet and linear feet?
Board feet measures volume (thickness × width × length), while linear feet measures only length. A 2×12 has more board feet per linear foot than a 2×4.
How much extra lumber should I buy?
Buy 10-15% extra for waste, cutting errors, and defects. For complex projects or beginners, 20% extra is safer.