Calculate board feet from thickness, width and length, then multiply by the number of identical boards. The default 2 x 6-inch x 8-foot example is 8 board feet per piece or 80 board feet for ten pieces. Add your own price for a material-only cost. This is a dimensional estimate, not an NHLA dealer tally.
How to calculate board feet
Board feet per piece = thickness (inches) x width (inches) x length (feet) / 12.
Total board feet = board feet per piece x number of pieces.
Material cost = total board feet x price per board foot. A board foot is the volume of a piece 1 inch thick, 12 inches wide and 12 inches long, or an equivalent volume.1, 2
If all three dimensions are inches, divide their product by 144 instead. Do not divide an all-inch product by 12. One board foot is 144 cubic inches, or 1/12 cubic foot. For length in feet and inches, use feet + inches / 12: 8 feet 6 inches is 8.5 feet, not 8.6.
Board-foot chart for 8-foot boards
Our calculated chart uses the entered dimensions exactly, with no dealer rounding or waste. The 2x rows use nominal thickness and width; they are not a measurement of the dressed board’s actual wood volume.
| Entered size | BF per 8-ft piece | BF for 10 pieces |
|---|---|---|
| 1 x 4 inches | 2.67 | 26.67 |
| 1 x 6 inches | 4.00 | 40.00 |
| 1 x 8 inches | 5.33 | 53.33 |
| 1 x 12 inches | 8.00 | 80.00 |
| 2 x 4 inches | 5.33 | 53.33 |
| 2 x 6 inches | 8.00 | 80.00 |
| 2 x 8 inches | 10.67 | 106.67 |
| 2 x 12 inches | 16.00 | 160.00 |
Three checked examples
1. Ten nominal 2 x 6 boards
Enter thickness 2 inches, width 6 inches, length 8 feet and 10 pieces. Per piece: 2 x 6 x 8 / 12 = 8 BF. Total: 8 x 10 = 80 BF. At an example quote of $4/BF, the estimated material cost is 80 x $4 = $320. That price is a made-up arithmetic example, not a market quote.
2. The same size label, measured as dressed wood
For an illustrative actual measurement of 1.5 x 5.5 inches x 8 feet: 1.5 x 5.5 x 8 / 12 = 5.5 BF per piece. Ten pieces contain 55 BF of geometric volume. The nominal inputs above give 80 BF. Neither input set should be combined with the other set’s quoted price without checking how the seller bills the wood.
3. Six 5/4 boards with fractional dimensions
For this dimensional example, enter 1.25 inches (5/4), 7 inches, 10.5 feet and 6 pieces. Per piece: 1.25 x 7 x 10.5 / 12 = 7.65625 BF. Total: 7.65625 x 6 = 45.9375 BF, displayed as 45.94 BF. At an example $8/BF quote, cost is $367.50. The cost uses the unrounded total, not six copies of the displayed 7.66 BF.
Nominal size, actual size and dealer tally
These are different measurement bases. Actual dimensions calculate the geometric volume present. Nominal dimensions describe the trade size, which can exceed a surfaced board’s measured thickness or width. Wengert explains that softwood board measure uses nominal dimensions, while hardwood tally uses actual width with standard thickness and a surface-measure rounding step.1, 2
This calculator does not perform that hardwood dealer tally. It does not truncate length, round each board’s surface measure, apply a minimum 1-inch billing thickness or alternate half-unit rounding. Wengert’s hardwood description rounds surface measure before multiplying by the standard thickness, so a dealer invoice can differ from a simple volume formula.2 Ask the supplier which rule applies to your order. Do not treat our decimal result as proof that a dealer’s tally is wrong.
What 4/4, 5/4 and 8/4 mean
Quarter notation expresses standard thickness in quarters of an inch: 4/4 = 1 inch, 5/4 = 1.25 inches, 6/4 = 1.5 inches and 8/4 = 2 inches. Wengert notes that standard thickness, kiln-dried allowances and surfacing affect the billing thickness.2 A surfaced 4/4 board is not necessarily 1 inch thick when you measure it. Use the quote’s basis for a cost estimate; use measured thickness for physical volume.
Mixed boards and cutting waste
The form assumes all pieces have the same dimensions and price. For mixed lengths or widths, calculate each group separately and add the unrounded totals. For example, four 1 x 6-inch x 8-foot boards make 16 BF, while two 1 x 8-inch x 10-foot boards make 13.333333 BF. Together they make 29.333333 BF before any allowance.
No waste percentage is added here. Start with a cutting list and allow for saw kerf, end trimming, defects and grain selection. An illustrative 20% allowance on 30 BF is 30 x 1.20 = 36 BF; 20% is an example, not our recommendation for every project. Extra volume cannot replace a board that is too short or too narrow for the required part.
Optional price and national-average note
*National average, dated reference only: Gordian lists July 2026 framing lumber at $915.88 per thousand board feet (MBF), equivalent to $0.91588/BF, rounded here to about $0.92/BF.3 This is a framing-lumber reference, not a hardwood quote or a promise of a home-center shelf price.
CalcCorp separately publishes a 2026 range of roughly $3.50-$18/BF for 4/4 FAS rough, kiln-dried domestic hardwood depending on species. It describes dealer price lists spanning regions, not a single national average.4 Treat that secondary-source range as context. Get a current quote matching species, grade, thickness, surfacing and quantity, then enter that price. Tax, delivery and milling are not included in the result.
FAQ
How many board feet are in an 8-foot 2 x 4?
Using nominal inputs, 2 x 4 x 8 / 12 = 5.333333 BF, displayed as 5.33. Using an actual 1.5 x 3.5-inch measurement gives 3.5 BF of physical volume. The two numbers describe different measurement bases.
Is a board foot the same as a linear foot?
No. A linear foot measures length only. A board foot measures volume, so the thickness and width matter too. One linear foot of entered 2 x 6-inch stock equals 1 BF; one linear foot of entered 1 x 6-inch stock equals 0.5 BF.
Can I enter metric measurements?
Yes. Use the metric switch for thickness and width in centimeters and length in meters. The result remains in board feet because the optional price is per board foot. The work line explains the US-unit conversion. Quantity and price do not change with the unit switch.
Will this calculate logs, deck coverage or structural strength?
No. It is for rectangular lumber dimensions, not Doyle or other log scales. It does not choose a beam, joist span, grade or load capacity. For coverage and board counts, use the deck board calculator, fence board calculator or flooring calculator; board feet alone do not account for gaps or exposed face width.
Sources
- WOODWEB: What Is a Board Foot? (Gene Wengert, definition and hardwood/softwood measurement bases)
- Woodworking Network: Board Foot Defined (Gene Wengert, dealer tally and standard thickness)
- Gordian: Lumber Price Updates (July 2026 national framing-lumber reference)
- CalcCorp: Hardwood Lumber Prices Per Board Foot (2026) (secondary-source regional hardwood range, not a national average)
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Estimates only. Confirm quantities and product details with your supplier before you order.
Compare lumber quotes on the same basis
Use our project planning and quote checklist to keep dimensions, quantity and included services together. Before applying a per-board-foot price, confirm whether the supplier bills nominal or actual dimensions and uses its own tally rounding. Compare the same species, grade and condition, then check milling, delivery and tax separately. This calculator gives dimensional volume at your entered price, not a dealer invoice.