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BestBoardFootCalculator.com
Best Board Foot Calculator
Quickly estimate board footage and (optionally) cost from your lumber dimensions. Enter thickness, width, length, number of pieces, and price per piece to see the totals.
What Is a Board Foot?
A board foot is a unit of volume used to price and measure hardwood lumber in the United States and Canada. One board foot equals a piece of wood measuring 12 in wide × 12 in long × 1 in thick — 144 cubic inches.
Unlike a linear foot, which only measures length, the board foot reflects the actual volume of wood you are buying. That is why mills and hardwood dealers price rough lumber by the board foot rather than by the piece or by length alone.
How to Calculate Board Feet
The formula depends on which unit you use for length:
- All inches: (Thickness × Width × Length) ÷ 144
- Length in feet: (Thickness × Width × Length in ft) ÷ 12
For multiple identical boards, calculate one board and multiply by the count. For a mixed lot, calculate each size separately and add the results. This calculator expects all three dimensions in inches; a length of 8 ft becomes 96 in, 10 ft becomes 120 in, and so on.
Worked Examples
| Lumber | Calculation | Board Feet |
|---|---|---|
| One 1″ × 6″ × 96″ | (1 × 6 × 96) ÷ 144 | 4.000 |
| Ten 1″ × 4″ × 96″ pine | (1 × 4 × 96 × 10) ÷ 144 | 26.667 |
| One 8/4 × 6″ × 120″ walnut | (2 × 6 × 120) ÷ 144 | 10.000 |
| Four 2″ × 10″ × 144″ | (2 × 10 × 144 × 4) ÷ 144 | 80.000 |
Nominal vs Actual Dimensions
Softwood construction lumber is sold by nominal size, which is larger than the milled, finished piece. A “2×4” is actually 1.5″ × 3.5″. For framing lumber priced per piece, the nominal label is what matters.
Hardwood sold by the board foot is usually priced using rough dimensions before surfacing, because the buyer is paying for wood volume. If you are not sure which dimensions your supplier is quoting, ask them — the difference can shift your total by 10–20%.
Hardwood is often labeled in quarter inches:
- 4/4 = 1″ thick
- 5/4 = 1.25″
- 6/4 = 1.5″
- 8/4 = 2″
Enter the decimal value in the thickness field above.
Frequently Asked Questions
- Is a board foot the same as a linear foot?
- No. A linear foot measures length only. A board foot measures volume, so thickness and width matter.
- Should I use rough or surfaced (S4S) dimensions?
- Most hardwood sellers price by rough dimensions before surfacing. For construction lumber, nominal dimensions are used. When in doubt, ask the supplier.
- Does this work for plywood or sheet goods?
- The math works, but sheet goods are usually priced by the square foot or per sheet rather than by the board foot.
- Can I use this for metric lumber?
- This calculator uses inches. Convert millimeters to inches first (divide by 25.4) or centimeters (divide by 2.54).
- Is this calculator accurate for pricing large purchases?
- It uses the standard board foot formula, but always double-check against the supplier’s own figures before a large purchase. Mixed species, defects, waste factor, and rounding rules vary between dealers.