Board Foot Calculator
Estimate lumber volume in board feet and optional project cost in seconds.
What is a board foot?
A board foot is a standard unit for measuring lumber volume. One board foot equals a piece of wood that is 1 inch thick, 12 inches wide, and 12 inches long. Builders, woodworkers, and sawmills use board feet to estimate how much lumber a project needs and what that lumber will cost.
Why this matters
When you buy hardwood, rough-sawn boards, or specialty stock, pricing is often shown as “$X per board foot.” If you can quickly calculate board feet, you can compare prices, avoid overbuying, and budget your project accurately.
How the board per foot calculator works
This calculator uses the standard formula:
Board Feet = (Thickness in inches × Width in inches × Length in feet × Quantity) ÷ 12
- Thickness: actual board thickness in inches
- Width: actual board width in inches
- Length: board length in feet
- Quantity: number of identical boards
If you enter a price per board foot, the calculator also estimates your total lumber cost.
Step-by-step usage
- Measure or verify the board’s actual thickness in inches.
- Measure the actual width in inches.
- Enter the board length in feet.
- Add quantity for multiple boards of the same size.
- Optionally enter price per board foot to estimate cost.
Example calculations
Example 1: Single board
A board is 2" thick, 6" wide, and 8' long.
Board feet = (2 × 6 × 8) ÷ 12 = 8 board feet
Example 2: Multiple boards
You have ten boards, each 1" × 8" × 10'.
Per board = (1 × 8 × 10) ÷ 12 = 6.67 board feet
Total = 6.67 × 10 = 66.7 board feet
Example 3: Cost estimate
If total volume is 66.7 board feet and price is $5.25 per board foot:
Total cost = 66.7 × 5.25 = $350.18 (approximately)
Common mistakes to avoid
- Using nominal dimensions (like 2×4) instead of actual measured size.
- Entering length in inches when the calculator expects feet.
- Forgetting to multiply by quantity.
- Rounding too early before calculating total project volume.
Practical tips for buying lumber
- Buy a little extra (typically 10%–15%) for defects and offcuts.
- Separate calculations by species if prices differ.
- Track cost per board foot across suppliers to spot better deals.
- Double-check moisture content and grade, not just volume and price.
FAQ
Is board foot the same as linear foot?
No. Linear foot only measures length. Board foot measures volume (thickness, width, and length together).
Can I use this for softwood construction lumber?
Yes, but construction lumber is often sold by piece or by linear length. This tool is especially useful where pricing is based on board feet.
Does this calculator work for metric units?
This version is inch/foot-based. Convert your measurements first, then calculate.