Board foot calculator
Add each board, pick a species, and get total board feet, a cost range, the stack's weight, and a cut list you can print or copy for the lumber yard.
| Thickness | Width (in) | Length | Qty | Board feet | Remove |
|---|
Price ranges are typical US retail for surfaced stock, reviewed October 2026. Thicker stock carries a per-BF premium. Lumber prices move often and vary 20–40% by region; enter your yard's price for an exact figure.
Board foot formula
A board foot is a volume: 144 cubic inches, or a piece 1" thick, 12" wide and 12" long.
Board feet = thickness (in) × width (in) × length (ft) ÷ 12
Or, with every measurement in inches: thickness × width × length ÷ 144.
Worked example
Three boards of 8/4 walnut, 7" wide and 9 ft long: 2 × 7 × 9 ÷ 12 = 10.5 BF each, 31.5 BF total. Add 15% waste for 36.2 BF. At $14/BF that's about $507.
What 4/4, 5/4 and 8/4 mean
Hardwood is sold by its rough thickness in quarter inches. 4/4 ("four-quarter") is 1" rough, 8/4 is 2" rough. Board feet are calculated on the rough (nominal) thickness (see what 4/4, 5/4 and 8/4 mean), even though surfaced 4/4 finishes around 13/16". The same goes for dimensional lumber: a 2x4 is billed as 2" × 4" even though it measures 1½" × 3½".
Board feet in common hardwood sizes
| Board | Board feet |
|---|---|
| 4/4 × 6" × 8 ft | 4 |
| 4/4 × 8" × 8 ft | 5.33 |
| 4/4 × 6" × 10 ft | 5 |
| 5/4 × 6" × 8 ft | 5 |
| 6/4 × 6" × 8 ft | 6 |
| 8/4 × 6" × 8 ft | 8 |
| 8/4 × 8" × 10 ft | 13.33 |
| 12/4 × 6" × 8 ft | 12 |
Board feet in dimensional lumber
| Piece | Board feet |
|---|---|
| 2x4 × 8 ft | 5.33 |
| 2x6 × 8 ft | 8 |
| 2x8 × 10 ft | 13.33 |
| 2x10 × 12 ft | 20 |
| 2x12 × 16 ft | 32 |
| 4x4 × 8 ft | 10.67 |
| 6x6 × 10 ft | 30 |
Price per board foot by species
Domestic hardwood
- Red oak$5–$8 / BF (4/4)
- White oak$7–$12 / BF (4/4)
- Hard maple$6–$10 / BF (4/4)
- Soft maple$4–$7 / BF (4/4)
- Black cherry$8–$14 / BF (4/4)
- Black walnut$12–$20 / BF (4/4)
- White ash$5–$9 / BF (4/4)
- Hickory$6–$10 / BF (4/4)
- Yellow poplar$3–$6 / BF (4/4)
- Red alder$4–$7 / BF (4/4)
- Yellow birch$5–$9 / BF (4/4)
- American beech$5–$8 / BF (4/4)
- Basswood$4–$7 / BF (4/4)
Softwood
- Bald cypress$4–$7 / BF (4/4)
- Eastern white pine$2–$4 / BF (4/4)
- Douglas fir$3–$6 / BF (4/4)
- Southern yellow pine$2–$4 / BF (4/4)
- Western red cedar$5–$10 / BF (4/4)
Exotic
- Sapele$8–$13 / BF (4/4)
- African mahogany (Khaya)$8–$12 / BF (4/4)
- Genuine mahogany$12–$20 / BF (4/4)
- Teak$25–$45 / BF (4/4)
- Ipe$12–$20 / BF (4/4)
- Purpleheart$10–$16 / BF (4/4)
- African padauk$12–$20 / BF (4/4)
- Zebrawood$20–$35 / BF (4/4)
- Wenge$25–$40 / BF (4/4)
Lumber buying guides
- How to Calculate Board Feet (With Examples)The board foot formula, worked examples for hardwood and dimensional lumber, and how to turn board feet into a price at the lumber yard.
- What Do 4/4, 5/4 and 8/4 Mean in Lumber?The quarter system for hardwood thickness, actual surfaced thicknesses for 4/4 through 16/4, and why 5/4 deck boards are different.
- Rough vs. Surfaced Lumber: S2S, S4S and SL1E ExplainedWhat RGH, S2S, S3S, S4S and SL1E mean on a lumber price list, what each costs you in thickness and waste, and which to buy for your shop.
- Hardwood Lumber Grades Explained: FAS, Select and #1 CommonHow NHLA hardwood grades work, the clear-wood yield of each grade, and when cheaper
- How Much Lumber Do I Need for a Dining Table?A worked example for a 6 ft × 36" dining table, from parts list to board feet, waste and cost, so you know what to buy before you go to the yard.
Frequently asked questions
How much waste should I allow?
About 15% for a typical furniture project in surfaced lumber. Rough lumber with knots, checks or wane can need 25–30%. If you're matching grain or working with figured boards, plan on 35% or more. Grade matters too: see hardwood lumber grades explained.
How do I convert a price per board foot to price per piece?
Multiply the board's board feet by the price per BF. A 4/4 × 6" × 8 ft board is 4 BF, so at $9/BF it costs $36.
Is a board foot the same as a linear foot?
No. A linear foot is a length (12") regardless of width or thickness. Board feet account for all three dimensions. A 1x6 that's 8 ft long is 8 linear feet but 4 board feet.
Why does thicker lumber cost more per board foot?
Thick stock comes from larger logs, takes much longer to dry, and has higher defect rates, so yards charge a premium per BF. 8/4 commonly runs 20–40% above 4/4 of the same species and grade.