Board Feet to Square Feet Calculator — Convert BF to Sq Ft
Enter the lumber volume in board feet.
Thickness is in inches. Quarters (4/4, 8/4) are common names.
1.00
sq ft
Also shows: 144.00cu in•0.08cu ft
Formula: 1.00 = 1.00 ÷ 1.00
Convert board feet to square feet based on board thickness. Pick a common thickness (4/4, 6/4, 8/4) or enter your own.
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Board Feet to Square Feet Conversion Table
Common board feet amounts at popular thicknesses. Tap a row or column to highlight.
| Board Feet | 1" (4/4) | 2" (8/4) | 1.5" (6/4) | 0.75" (3/4) |
|---|---|---|---|---|
| 1 BF | 1.00sq ft | 0.50sq ft | 0.67sq ft | 1.33sq ft |
| 5 BF | 5.00sq ft | 2.50sq ft | 3.33sq ft | 6.67sq ft |
| 10 BF | 10.00sq ft | 5.00sq ft | 6.67sq ft | 13.33sq ft |
| 25 BF | 25.00sq ft | 12.50sq ft | 16.67sq ft | 33.33sq ft |
| 50 BF | 50.00sq ft | 25.00sq ft | 33.33sq ft | 66.67sq ft |
| 100 BF | 100.00sq ft | 50.00sq ft | 66.67sq ft | 133.33sq ft |
Tip: The same BF covers less area when the board is thicker.
How to Convert Board Feet to Square Feet
Use this quick formula. The only thing you need is thickness.
- 1
Step 1 — Know your board thickness
Thickness is the board’s thickness in inches. If you select 4/4, we use 1" for the math.
- 2
Step 2 — Apply the formula
Square Feet = Board Feet ÷ Thickness. Example: 100 BF at 2" thick covers 50 sq ft.
- 3
Step 3 — Read the result
The result is surface area coverage. Add waste (10–15%) if you’re buying for a project.
Understanding Board Feet vs Square Feet
They measure different things: volume vs area.
What is a board foot?
A board foot is a volume unit: 144 cubic inches (1" × 12" × 12"). Lumber is often sold by BF.
What is a square foot?
A square foot measures surface area (12" × 12"). It’s used for coverage like flooring and decking.
When should you use each?
Use BF to price volume, and sq ft to estimate coverage. Thickness is what connects them.
Common Mistakes to Avoid
A few gotchas that often cause wrong conversions.
Using nominal thickness instead of actual thickness
If your lumber is planed, actual thickness can be less than the nominal value. Use the thickness your supplier lists when you need accuracy.
Forgetting that BF is volume
The same BF covers different square footage depending on thickness. Always confirm the thickness before converting.
Skipping waste on projects
If you’re buying material, add 10–15% extra for waste, defects, and offcuts.
Disclaimer
This calculator gives an estimate for planning. Actual coverage can change with planing, sanding, and the difference between nominal vs actual thickness. Always confirm material specs with your supplier.
Sources
- USDA Forest Service — Wood Handbook: Wood as an Engineering Material (board foot definition).
- National Hardwood Lumber Association (NHLA) — Hardwood lumber measurement basics.
- University extension woodworking resources — board foot and coverage explanations.
Frequently Asked Questions
Divide board feet by thickness in inches: Sq Ft = BF ÷ Thickness. Because BF is a volume unit, thickness changes how much surface area that volume can cover.
Pro tip
When buying lumber, add 10–15% extra for waste (cuts, defects, and mistakes) so you don’t run short.