Board Feet Calculator
Estimate lumber volume in board feet, plus cubic feet/meters, and optional cost.
Quick guide
- Board feet is a lumber volume unit used for pricing and ordering.
- Use actual thickness/width (not nominal) for the most accurate estimate.
- Add waste for knots, defects, and cuts (often 5-10%).
Board Feet Calculator
Estimate lumber volume in board feet, plus cubic feet/meters, and optional cost.
Units
Results
- Board feet
- 44
- Cubic feet
- 3.67
- Cubic meters
- 0.104
How board feet works
- Board feet = (thickness in inches × width in inches × length in feet) ÷ 12.
- Multiply by quantity, then add a waste factor if needed.
- If the seller prices per board foot, multiply board feet by that price.
Assumptions to double-check
- Nominal lumber sizes (e.g., 2×6) are not the same as actual dimensions.
- Rough-sawn lumber may be thicker and varies by mill.
- Some products are priced per linear foot or per piece instead of board feet.
Buying tips
- Confirm the actual dimensions and species/grade with the supplier.
- For finish work, consider adding extra for grain matching and defects.
- Round up to whole boards and keep a little extra for future repairs.
Last updated: Dec 2025
FAQ
What is a board foot?
A board foot is a unit of lumber volume equal to a board 1 inch thick, 12 inches wide, and 12 inches long.
Should I use nominal or actual size?
Use actual dimensions for accuracy. Nominal sizes (like 2×6) are larger than the finished actual size.
Why add waste?
Waste helps cover defects, knots, cuts, and a few mistakes. 5-10% is common depending on the project.
Related
In Roofing & exterior
Related guides
How to estimate roofing shingles
Squares, bundles, and how to add waste.
How many shingles for a shed roof
A fast approach for small simple roofs.
How to estimate deck boards
Deck area, board coverage, and spacing basics.
How to estimate fence materials
Panels, posts, gates, and layout assumptions.
How many fence posts do I need?
Post spacing, corners, and gate posts explained.
Browse all guides →Disclaimer
Results are estimates for informational purposes only. Always verify measurements and product specifications.