Board Foot Calculator
Calculate board feet for lumber, then estimate purchase quantity and material cost.
Board Foot Calculator
How board feet are calculated
For one board, board feet = thickness in inches × width in inches × length in feet ÷ 12. If all three dimensions are entered in inches, divide the product by 144 instead.
The total is the board feet per board multiplied by the number of boards. Volume is also shown as cubic feet and cubic metres; one board foot is 0.083333 cubic feet.
Common board foot chart
Approximate board feet per dressed board using the actual dimensions behind the common nominal presets.
Swipe or scroll horizontally to see more columns.
| Nominal size | Actual size | 6 ft | 8 ft | 10 ft | 12 ft | 16 ft |
|---|---|---|---|---|---|---|
| 1×4 | ¾ × 3½ in | 1.31 | 1.75 | 2.19 | 2.63 | 3.50 |
| 1×6 | ¾ × 5½ in | 2.06 | 2.75 | 3.44 | 4.13 | 5.50 |
| 1×8 | ¾ × 7¼ in | 2.72 | 3.63 | 4.53 | 5.44 | 7.25 |
| 2×4 | 1½ × 3½ in | 2.63 | 3.50 | 4.38 | 5.25 | 7.00 |
| 2×6 | 1½ × 5½ in | 4.13 | 5.50 | 6.88 | 8.25 | 11.00 |
| 2×8 | 1½ × 7¼ in | 5.44 | 7.25 | 9.06 | 10.88 | 14.50 |
| 2×10 | 1½ × 9¼ in | 6.94 | 9.25 | 11.56 | 13.88 | 18.50 |
| 2×12 | 1½ × 11¼ in | 8.44 | 11.25 | 14.06 | 16.88 | 22.50 |
Worked example
Five boards measuring 1.25 in × 10 in × 8 ft equal 1.25 × 10 × 8 ÷ 12 × 5 = 41.67 board feet. At an entered price of $4.15 per board foot, the net material cost is $172.92.
This is a static example for checking the formula. It is not a prefilled calculator value.
Nominal and actual lumber dimensions
A nominal 2×4 is commonly dressed to about 1.5 in × 3.5 in, not 2 in × 4 in. The common-size presets show the actual dimensions used for the calculation, and you can replace them with a supplier quote or measured size.
The presets follow the US dressed-lumber size convention described in NIST Voluntary Product Standard PS 20-25. They are not a universal rule for rough-sawn hardwood, every supplier or every market.
Board foot and linear foot are different
A linear foot measures length only. A board foot includes thickness and width, so two boards with the same length can have very different board-foot quantities. Use the dimensions of the material rather than multiplying length alone.
Price and cutting allowance
Leave price blank when you only need quantity. If you enter a price, the calculator shows net material cost unless you also add a cutting allowance or supplier order increment.
An allowance is not a species yield, grading rule or contractor takeoff. Confirm the supplier’s selling unit, the project cut list and the amount of usable material before placing an order.
Hardwood tally and log rules are separate
This page uses the transparent geometric board-foot formula. Hardwood tally systems, log rules such as Doyle, and sawmill recovery estimates use different assumptions and should not be inferred from this result.
Sources and scope
Nominal-size context: NIST PS 20-25. The calculator is a dimensional planning aid; confirm supplier dimensions, selling increments and any hardwood tally rules before ordering.
FAQ
How many board feet are in a 2×4?
It depends on length and on whether you use nominal or actual dimensions. Using the common dressed size of 1.5 in × 3.5 in, an 8 ft board is 3.50 board feet. Select the 2×4 preset to see the dimensions used.
How do I calculate hardwood board feet?
For a straightforward dimensional estimate, use thickness in inches × width in inches × length in feet ÷ 12. Hardwood sellers may apply grading, tally or minimum-size rules, so confirm the supplier’s method when buying rough-sawn or surfaced hardwood.
Can I use metric dimensions?
Yes. Choose Metric or select metric field units. The calculator converts the entered dimensions to the same canonical board-foot formula and also shows cubic metres. Board foot remains the primary result because it is the unit being estimated.
Does the result include waste?
The main total is net board feet from the dimensions and quantity entered. Open Plan what to order to add a cutting allowance and, if needed, round up to a supplier selling increment.