Board Feet Calculator
Calculate lumber board feet from thickness, width, length, and quantity — with total cost, metric volume equivalents, a common-size reference chart, and a downloadable PDF report.
A board foot measures lumber volume: 1 BF = 144 cubic inches (a 1″ × 12″ × 12″ board). Enter nominal dimensions — for estimation only.
| Nominal Size | BF per ft | 8 ft Board | 12 ft Board |
|---|
How to use the board feet calculator
Enter the board’s thickness, width and length, add a quantity and a price, and get the total board feet, what it costs, and the volume in both imperial and metric — plus a reference chart for every common lumber size.
Enter thickness and width
In inches. Tap a common size chip for dimensional lumber, or type the actual measurement for hardwood.
Set the length and quantity
Switch length between feet and inches. Quantity multiplies the whole calculation for a full order.
Add a price per board foot
Optional. Leave it blank to skip the cost, or enter the yard’s rate to price the order as you go.
Compare lengths & save a PDF
The chart shows board feet at every standard length for your cross-section, and the report includes the reference chart.
How board feet are calculated
A board foot is a unit of volume, not length or area: 144 cubic inches, which is a board one inch thick, twelve inches wide and twelve inches long. Everything else follows from that one definition.
Worked example — five 8-foot 2×4s at $4.50/BF
Per board, the long way: 2 × 4 × 96 ÷ 144 = 5.33 BF
Per board, the shortcut: 2 × 4 × 8 ÷ 12 = 5.33 BF
The order: 5.33 × 5 pieces = 26.67 BF
The cost: 26.67 × $4.50 = $120.00
That same pile is 40 linear feet, 2.22 cubic feet, or 62.9 liters of wood — four numbers for one stack of lumber.
Board foot conversion charts
The lookups that come up most — board feet per linear foot, whole boards at standard lengths, hardwood quarter thicknesses, nominal against actual, and the metric equivalents.
| Nominal size | BF per foot | Cross-section | 10 ft board |
|---|---|---|---|
| 1×2 | 0.167 BF | 2 in² | 1.67 BF |
| 1×4 | 0.333 BF | 4 in² | 3.33 BF |
| 1×6 | 0.500 BF | 6 in² | 5.00 BF |
| 1×8 | 0.667 BF | 8 in² | 6.67 BF |
| 1×10 | 0.833 BF | 10 in² | 8.33 BF |
| 1×12 | 1.000 BF | 12 in² | 10.00 BF |
| 2×4 | 0.667 BF | 8 in² | 6.67 BF |
| 2×6 | 1.000 BF | 12 in² | 10.00 BF |
| 2×8 | 1.333 BF | 16 in² | 13.33 BF |
| 2×10 | 1.667 BF | 20 in² | 16.67 BF |
| 2×12 | 2.000 BF | 24 in² | 20.00 BF |
| 4×4 | 1.333 BF | 16 in² | 13.33 BF |
| 6×6 | 3.000 BF | 36 in² | 30.00 BF |
Board feet per foot is just the cross-section area divided by 12 — which is why a 1×8 and a 2×4 come to the same figure. A 1×12 is the easy one: exactly one board foot per linear foot.
| Nominal size | 8 ft | 10 ft | 12 ft | 16 ft |
|---|---|---|---|---|
| 1×6 | 4.00 BF | 5.00 BF | 6.00 BF | 8.00 BF |
| 1×8 | 5.33 BF | 6.67 BF | 8.00 BF | 10.67 BF |
| 1×12 | 8.00 BF | 10.00 BF | 12.00 BF | 16.00 BF |
| 2×4 | 5.33 BF | 6.67 BF | 8.00 BF | 10.67 BF |
| 2×6 | 8.00 BF | 10.00 BF | 12.00 BF | 16.00 BF |
| 2×8 | 10.67 BF | 13.33 BF | 16.00 BF | 21.33 BF |
| 2×10 | 13.33 BF | 16.67 BF | 20.00 BF | 26.67 BF |
| 2×12 | 16.00 BF | 20.00 BF | 24.00 BF | 32.00 BF |
| 4×4 | 10.67 BF | 13.33 BF | 16.00 BF | 21.33 BF |
| 6×6 | 24.00 BF | 30.00 BF | 36.00 BF | 48.00 BF |
Lumber is stocked in even lengths — 8, 10, 12, 14 and 16 feet. If a part needs 9 feet you buy the 10 and account for the offcut, so estimate against the length you can actually buy.
| Called | Rough thickness | Typical surfaced (S2S) | BF per square foot |
|---|---|---|---|
| 4/4 — four quarter | 1 in | 13/16 in | 1.00 BF |
| 5/4 — five quarter | 1-1/4 in | 1-1/16 in | 1.25 BF |
| 6/4 — six quarter | 1-1/2 in | 1-5/16 in | 1.50 BF |
| 8/4 — eight quarter | 2 in | 1-3/4 in | 2.00 BF |
| 10/4 — ten quarter | 2-1/2 in | 2-1/4 in | 2.50 BF |
| 12/4 — twelve quarter | 3 in | 2-3/4 in | 3.00 BF |
| 16/4 — sixteen quarter | 4 in | 3-3/4 in | 4.00 BF |
The quarter figure is rough thickness before surfacing, and it’s what you’re charged for. Surfaced dimensions vary between mills, so measure what arrives rather than assuming the standard.
| Nominal | Actual size | Nominal BF (8 ft) | Actual volume (8 ft) |
|---|---|---|---|
| 1×4 | 3/4 × 3-1/2 in | 2.67 BF | 1.75 BF |
| 1×6 | 3/4 × 5-1/2 in | 4.00 BF | 2.75 BF |
| 1×12 | 3/4 × 11-1/4 in | 8.00 BF | 5.63 BF |
| 2×4 | 1-1/2 × 3-1/2 in | 5.33 BF | 3.50 BF |
| 2×6 | 1-1/2 × 5-1/2 in | 8.00 BF | 5.50 BF |
| 2×8 | 1-1/2 × 7-1/4 in | 10.67 BF | 7.25 BF |
| 2×10 | 1-1/2 × 9-1/4 in | 13.33 BF | 9.25 BF |
| 2×12 | 1-1/2 × 11-1/4 in | 16.00 BF | 11.25 BF |
| 4×4 | 3-1/2 × 3-1/2 in | 10.67 BF | 8.17 BF |
Use the nominal column when buying or pricing dimensional softwood — that’s the trade convention. The actual column is what you need for weight, shipping volume, or working out how much wood is really there.
| Unit | What it measures | Equal to |
|---|---|---|
| 1 board foot | Volume of sawn timber | 144 in³ · 0.0833 ft³ · 2.36 L |
| 1 cubic foot | Volume | 12 board feet · 1,728 in³ |
| 1 cubic meter | Volume — metric timber standard | 423.8 board feet · 35.31 ft³ |
| 1 MBF | Wholesale lumber quantity | 1,000 board feet · 2.36 m³ |
| 1 linear foot | Length only | Varies with thickness and width |
| 1 square foot | Surface area only | 1 BF only if the stock is 1 in thick |
Firewood is the odd one out: a cord is 128 cubic feet of stacked wood including the air gaps, so it doesn’t convert cleanly to board feet and shouldn’t be treated as a lumber measure.
A 2×4 leaves the mill at a full two by four inches, then loses material to drying and surfacing and arrives at 1½ by 3½. The name stuck to the rough size. That means a 2×4 holds about 34% less wood than its label implies — but the trade still prices it as a 2×4.
- Softwood is calculated nominal — it’s the convention every yard and estimator uses, so switching to actual dimensions makes your figures disagree with the quote.
- Hardwood is calculated actual — measured thickness in quarters and true width, before surfacing. There’s no nominal system for it.
- Use actual dimensions for physical questions — weight, shipping volume, or whether a stack will fit. Nominal is a pricing label, not a measurement.
Everything the calculator works out
One set of dimensions gives you the quantity, the cost, the volume in four units, and a comparison across every standard length — plus a report you can take to the yard.
The figures behind every board foot
Built for anyone buying wood by volume
Retail lumber is sold by the piece, hardwood by the board foot, and mills by the thousand. Getting between those three is the difference between a quote you can check and one you have to trust.
Working out how much lumber a deck, shed or partition needs, and whether a per-piece price at one yard beats a per-board-foot price at another.
- Use nominal sizes for dimensional lumber
- Buy the next standard length up
- Add about 10% for offcuts
Buying rough hardwood priced strictly by the board foot, where thickness is quoted in quarters and every board is a different width.
- 4/4 is one inch, 8/4 is two
- Measure rough, before surfacing
- Add 15–20% for defects and yield
Pricing a materials package against published market rates in MBF, or reconciling a metric quote in cubic meters with a domestic one in board feet.
- 1 MBF = 1,000 BF = 2.36 m³
- Confirm nominal vs actual on the spec
- Save the PDF against the purchase order
7 tips for estimating lumber without errors
The assumptions that quietly put an order out by a fifth — and the checks that catch them before the delivery arrives.
Board feet FAQ
The measuring, pricing and ordering questions people ask most when lumber is quoted by volume rather than by the piece.
Multiply thickness in inches by width in inches by length in inches, then divide by 144. One board foot is 144 cubic inches — a board 1 inch thick, 12 inches wide and 12 inches long.
If the length is already in feet there’s a shortcut: T × W × L(ft) ÷ 12. An 8-foot 2×4 is 2 × 4 × 8 ÷ 12 = 5.33 BF.
A 2×4 holds 0.667 board feet per linear foot. An 8-foot 2×4 is 5.33 BF, a 10-foot is 6.67, a 12-foot is 8.0 and a 16-foot is 10.67.
Those figures use the nominal 2 by 4 size, which is the standard convention for dimensional softwood even though the board actually measures 1½ × 3½ inches.
No. A linear foot measures length only, so a 12-foot board is 12 linear feet however thick or wide it is. A board foot measures volume, so thickness and width both count.
A 12-foot 2×4 is 12 linear feet but 8 board feet; a 12-foot 2×12 is also 12 linear feet but 24 board feet. Trim and dimensional lumber are often priced per linear foot, hardwood almost always per board foot.
For dimensional softwood, use the nominal size. A 2×4 is calculated as 2 by 4 even though it measures 1½ by 3½ after drying and surfacing — that’s the trade convention and what suppliers quote against.
For hardwood, use the actual measured thickness in quarters and the actual width, taken before surfacing. That’s why a 4/4 board sold as an inch thick may arrive at 13/16.
It’s hardwood thickness in quarters of an inch. 4/4 is one inch, 5/4 is 1¼, 6/4 is 1½, 8/4 is two inches, 12/4 is three. It’s spoken as “four quarter”, “five quarter” and so on.
The number is rough thickness before surfacing. A 4/4 board surfaced on two sides typically finishes at 13/16 inch, but it’s still bought, sold and calculated as 4/4.
One cubic meter is about 423.8 board feet. Going the other way, one board foot is 0.00236 m³, or 2.36 liters.
Board feet are an imperial timber measure, so metric markets quote sawn timber in cubic meters instead. Converting to cubic meters is the reliable way to compare a North American quote against a European or Asian one.
MBF means a thousand board feet — the M is the Roman numeral for one thousand. It’s the standard unit for wholesale lumber pricing, mill output and commodity futures.
A price of $550 per MBF works out to 55 cents per board foot. Retail yards price by the piece or the board foot, so MBF is mainly useful when checking a quote against published market rates.
For dimensional softwood cut to length, around 10 percent covers offcuts and the occasional bad board. For rough hardwood, 15 to 20 percent is more realistic — you lose material to defects, checks, wane, and the jointing and planing that follow.
Add more if your parts are long, if grain or color matching matters, or if yield is limited by cutting around knots. Buying the extra now is almost always cheaper than returning for a board from a different lot.
Estimation Only — Confirm Dimensions and Pricing: This calculator works out lumber volume from the dimensions you enter, using the standard definition of 1 board foot = 144 cubic inches. Results depend entirely on whether you enter nominal or actual dimensions: dimensional softwood is conventionally priced on nominal sizes (a 2×4 measures 1½ × 3½ inches), while hardwood is measured at actual rough thickness and width. Actual sizes, surfacing standards and grading rules vary by supplier, species and region. Board-foot totals do not include a waste allowance — add your own overage for offcuts, defects and yield loss. Prices shown are whatever rate you enter and are not quotes. For estimation purposes only; confirm quantities and pricing with your supplier before ordering.