Board Foot Calculator
Calculate board feet for lumber, hardwood, timber and woodworking projects. Enter the actual thickness, width, length and piece count to estimate total board feet, add a waste allowance and optionally calculate material cost.
Your lumber estimate will appear here.
What is a board foot?
A board foot is a lumber volume measurement equal to a board that is 1 foot long, 1 foot wide and 1 inch thick. It is commonly used when estimating hardwood, rough-sawn lumber and woodworking stock in the United States and Canada.
Board foot formula
When thickness and width are entered in inches and length in feet:
Board feet per piece = (Thickness × Width × Length) ÷ 12.
Total board feet = Board feet per piece × Number of pieces. Add the waste percentage for a planning quantity. For metric dimensions, the calculator converts millimetres and metres to the same formula units before calculating.
Worked example
One piece of lumber measuring 1 inch thick, 6 inches wide and 8 feet long contains 4 board feet. Twelve pieces contain 48 board feet before waste. With a 10% allowance, the planning quantity is 52.8 board feet.
Use actual, not nominal, dimensions
Lumber sold under a nominal size can have different finished dimensions after surfacing. Enter the actual measured thickness and width for the most useful estimate. For rough-sawn stock, measure the stock you are pricing.
Frequently asked questions
How many board feet are in a 2 × 4 × 8?
Using nominal dimensions as a simple calculation: (2 × 4 × 8) ÷ 12 = 5.33 board feet. Actual finished dimensions may be smaller, so use the measured sizes for purchasing.
Does the calculator include waste?
Yes. Enter a waste allowance to add it to the total volume. Select a percentage based on cuts, defects, grain matching and project complexity.
Can I calculate metric lumber?
Yes. Choose millimetres and metres, then enter thickness, width and length in those units.
Is board foot the same as linear foot?
No. Linear feet measure length only. Board feet measure lumber volume and include thickness and width.
Related tools: Deck Material Calculator · Gravel Calculator.
Lumber prices, grading, moisture content, surfacing and supplier rounding vary. This calculator estimates volume; confirm dimensions, grade and invoicing rules with your lumber supplier.