Lumber Calculator
Calculate board feet and cost for any boards, or size up a stud wall — studs, plates, and total board feet — with live pricing.
How to Calculate Lumber and Board Feet
A board foot is the standard unit for buying and pricing rough lumber — it equals 144 cubic inches, or a piece 1 inch thick, 12 inches wide, and 1 foot long. The formula is thickness (in) × width (in) × length (ft) ÷ 12, multiplied by how many boards you need. Multiply the total board feet by your price per board foot to estimate the cost.
For a stud wall, the number of studs is wall length × 12 ÷ spacing, plus one, then add a couple extra for corners and blocking. You'll also need plate stock — one bottom plate and two top plates run the full wall length, so plate material is about three times the wall length. Switch between the two modes above to size boards or frame a wall, with live cost estimates.
Frequently Asked Questions
How do I calculate board feet?
Board feet = thickness (inches) × width (inches) × length (feet) ÷ 12. For example, a 2×6 that is 8 feet long is (2 × 6 × 8) ÷ 12 = 8 board feet. Multiply by quantity for the total.
How many studs do I need for a wall?
Take the wall length in feet, multiply by 12, divide by your stud spacing (16 or 24 inches), then add one stud to close the end. Add two or more extra studs for corners, blocking, and openings.
What is a board foot?
A board foot is a volume of lumber equal to 144 cubic inches — a board 1 inch thick, 12 inches wide, and 1 foot long. It is the standard unit for pricing hardwood and rough-sawn lumber, regardless of the board's actual dimensions.
Turn Your Measurements Into a Real Floor Plan
Once you know your dimensions, generate a labeled, to-scale floor plan in seconds — then export it to DXF or build it in 3D. No CAD experience needed.
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