Board Feet Calculator
Calculate lumber volume in board feet (BF).
This board feet calculator converts lumber dimensions (thickness, width, and length) into board feet - the standard unit lumber is priced and sold by - and can total the board feet across multiple pieces for a woodworking or construction project.
Enter the thickness, width, and length of your lumber (and quantity), and the calculator returns the total board feet.
Worked Calculation Examples
| Scenario | Result | Calculation Step |
|---|---|---|
| 2 in × 6 in × 96 in (8 ft) board | 8 board feet | Board feet = (2 × 6 × 96) ÷ 144 = 1,152 ÷ 144 = 8. |
| 1 in × 8 in × 120 in (10 ft) board | ≈6.67 board feet | Board feet = (1 × 8 × 120) ÷ 144 = 960 ÷ 144 ≈ 6.67. |
The Board Feet Formula
One board foot equals a piece of lumber 1 inch thick, 12 inches wide, and 12 inches long (144 cubic inches). The formula is: board feet = (thickness in inches x width in inches x length in inches) / 144. For length measured in feet instead of inches, use: (thickness x width x length in feet) / 12. The board foot unit dates to 19th-century American lumber trade, when a standardized volume measurement became necessary as sawmills began shipping lumber over long distances by rail; it remains the standard pricing unit in North American lumber yards today, even though most other countries measure lumber in cubic meters.
Why Board Feet Instead of Square Feet
Board feet accounts for thickness, not just surface area, which matters because lumber cost scales with volume, not just the face dimensions - a 2-inch thick board contains twice the wood (and typically costs roughly twice as much per unit length) as a comparable 1-inch thick board of the same width.
How to Use the Board Feet Calculator
- Open the Board Feet Calculator and enter the values requested in the input fields.
- Check the units, percentages, dates, or time periods before reading the answer.
- Review the instant result and adjust any value to compare another scenario.
- Use the formula, example, and FAQs below to understand how the board feet calculator works.
Frequently Asked Questions
How do I calculate board feet?
Multiply thickness (inches) x width (inches) x length (inches), then divide by 144. If length is measured in feet, divide by 12 instead.
What is one board foot?
One board foot is a volume equal to a board 1 inch thick, 12 inches wide, and 12 inches long - 144 cubic inches of lumber.
Why is lumber priced in board feet instead of square feet?
Because board feet accounts for thickness as well as face area, giving an accurate volume measurement - two boards with the same length and width but different thickness contain different amounts of wood and should cost differently.
How do I use this board feet calculator?
Enter the known values, review the units or settings, and the calculator updates the result instantly. The formula and example on this page show how the answer is produced.
What does the Board Feet Calculator calculate?
Calculate lumber volume in board feet (BF). It is designed for fast browser-based calculations without sign-up, downloads, or manual spreadsheet setup.
What formula does this board feet use?
The formula is: Board Feet = (Thickness × Width × Length in inches) ÷ 144. Thickness, Width, and Length are all measured in inches. Dividing their product by 144 (the cubic inches in one board foot: 1in × 12in × 12in) converts raw cubic inches into board feet, the standard lumber-pricing unit that accounts for volume rather than just face area.
Related Calculators
Stair Calculator
Calculate stair riser height, tread depth, and stringer angle.
Roofing Calculator
Estimate roofing square footage, shingles bundles, and pitch slope.
Concrete Calculator
Estimate concrete volume in cubic yards, cubic feet, and 60lb/80lb bags.
Paint Calculator
Calculate paint gallons required for wall square footage.
Flooring & Square Footage Calculator
Estimate tile, hardwood, or carpet square footage and cost.
Gravel & Mulch Calculator
Calculate cubic yards and tons of gravel or garden mulch.
Last updated: September 29, 2026.