Lumber Calculator
Calculate lumber needs including board feet, stud counts, and framing materials. Estimate wood for walls, decks, and woodworking projects.
Recommended Tools & Supplies
IRWIN Fiberglass Claw Hammer, 16 oz
Durable fiberglass handle hammer for general construction and carpentry work.
View on AmazonAs an Amazon Associate, I earn from qualifying purchases. This helps keep our calculators free!
How to Use This Calculator
Calculate lumber needs for framing, decking, and woodworking projects:
- Select the type of calculation needed (board feet, framing, or lineal feet).
- Enter the dimensions of your project or individual boards.
- For framing, enter wall length and stud spacing (16" or 24" on center).
- Click 'Calculate' to see total board feet, number of boards, or framing members needed.
Why This Matters
Lumber is sold in various ways - by the board foot for hardwoods, by the piece for dimensional lumber, and by the lineal foot for trim and molding. Understanding these measurements helps you order accurately and compare prices between suppliers. Over-ordering wastes money on expensive wood, while under-ordering delays projects and means more trips to the lumber yard.
- Calculate board feet for accurate hardwood ordering
- Estimate stud counts for wall framing projects
- Plan joist and rafter requirements for floors and roofs
- Compare lumber costs across different suppliers
- Avoid material shortages that delay projects
Worked Examples
Wall Framing
Building a 20-foot wall with 16" on-center stud spacing.
Hardwood Table Top
Building a 4' × 6' table top from 4/4 (1") walnut.
Deck Framing
12' × 16' deck, joists 16" on center, double rim joists.
Common Mistakes to Avoid
- Confusing board feet with square feet - board feet includes thickness in the calculation.
- Forgetting that nominal sizes aren't actual sizes - a 2×4 is actually 1.5" × 3.5".
- Not accounting for waste from cuts, knots, and defects - add 10-15% for most projects.
- Using standard lumber grade for projects requiring better quality - check grade stamps.
- Forgetting blocking, bridging, and connection hardware in framing estimates.