Board Foot Calculator.
Real-time lumber calculations with a visual preview and a project cut list that saves to your browser.
Board Dimensions
0 BF
0 BF
$0.00
Cost = Total BF × Price / BF · Waste factor applied to cut list totals
Lumber Preview
Quickly calculate board feet, visualize lumber dimensions, and manage your project cut list — all in one place. Enter thickness, width, and length, choose your units, set a price, and get instant cost estimates. Add multiple boards to build a cut list that auto-saves to your browser.
A board foot calculator is an essential tool for anyone working with lumber — from professional contractors and cabinet makers to weekend DIYers. Board footage is the standard unit of volume for hardwood lumber in North America, and getting it right means the difference between a profitable project and costly waste. Our lumber board foot calculator delivers fast, accurate results with a clean interface and zero clutter.
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| Thickness | Width | Length | Qty | BF | Cost |
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A board foot calculator that actually works the way you do.
Drop in your dimensions, get your board footage, price it out, and build a cut list — all in one place. No sign-up, no bloat, just the math you need.
Everything you need to know about board feet.
What exactly is a board foot?
A board foot is a unit of volume used for lumber in the US and Canada. One board foot equals a piece of wood that is 12 inches long, 12 inches wide, and 1 inch thick — or 144 cubic inches. Think of it as a slice of wood about the size of a cutting board, but an inch thick.
The formula is simple:
So a 2×6 that is 10 feet long works out to 1.5 × 5.5 × 10 ÷ 12 = 6.88 board feet. The calculator on this page does this math instantly, which is handy when you are pricing out a whole project and not just one board.
Why lumber is sold by the board foot
If you have ever bought hardwood from a lumberyard, you know they do not sell by the linear foot. A 6-foot plank of 8/4 walnut costs more than a 6-foot plank of 4/4 walnut, even though they are the same length. That is because board feet account for thickness and width too. It is the only fair way to price wood, since two boards of the same length can have wildly different volumes.
Softwood lumber at the home center is usually sold by dimensional size (a 2×4 is 2×4, regardless of length), but hardwood and exotic species are almost always priced per board foot. If you are building furniture, cabinets, or trim work from rough lumber, you need to think in board feet.
Actual vs nominal dimensions — the gotcha that trips everyone up
Here is something that surprises a lot of new woodworkers: a 2×4 is not actually 2 inches by 4 inches. It is 1.5 inches by 3.5 inches. The "2×4" is the nominal size — what the board was called before it was planed smooth at the mill. The actual dimensions are smaller.
This matters for board foot calculations. If you punch 2 × 4 × 8 into a calculator that expects actual dimensions, you will overestimate. This tool uses actual dimensions for its lumber presets (1.5 × 3.5 for a 2×4, 1.5 × 5.5 for a 2×6, 3.5 × 3.5 for a 4×4, and so on), so you get accurate results without having to look up the real sizes.
If you are working with rough lumber that has not been surfaced, measure it yourself after jointing and planing to whatever thickness you need. That actual measurement is what goes into the board foot formula.
How to price a project using board feet
Say you are building a farmhouse table out of white oak. Your lumberyard wants $8.50 per board foot. You need eight boards, each 8/4 thick, 6 inches wide, and 8 feet long. That is 1.75 × 5.5 × 8 ÷ 12 = 6.42 board feet per board, times eight boards, times $8.50 — roughly $436 just for the top.
The price-per-board-foot field in this calculator lets you plug in whatever your supplier charges, and it shows the cost per board and the running total. That way you can compare oak at one price versus walnut at another without having to reach for a separate calculator.
Cut lists and waste factor — buying smarter
No project uses lumber with 100% efficiency. There are always offcuts, knots that you have to work around, and off-by-one mistakes. A typical waste factor for woodworking is 5% to 10%, depending on the complexity of the project. Framing a house might only waste 5%, but building a piece of furniture with lots of small parts can waste 20% or more.
This tool includes a waste factor slider so you can add a buffer to your total. Build your cut list with all the pieces you need, set the waste percentage, and the calculator shows the adjusted total board footage and cost. It is one of those features that seems small until you actually use it on a real project and realize how much it simplifies the math.
Metric measurements — not just for Europe
Even in the US, a lot of imported lumber is sold in metric dimensions. Plywood is commonly 1220 × 2440 mm, and some hardwood suppliers list thickness in millimeters. This calculator handles both imperial and metric, and converts between them on the fly. Toggle the unit switch and all your inputs and results update automatically. No need to remember conversion factors.
The visualizer — a quick sanity check
Numbers are one thing. Actually seeing the board helps catch mistakes. The isometric preview on this tool shows your lumber as a 3D block, scaled to the dimensions you entered. It is not meant to be a CAD drawing — it is a quick visual check that the proportions look right. If you meant to enter 8 feet but typed 80, the visualizer makes it obvious.
Doyle, Scribner, and International log rules — a quick note
If you are scaling logs (round timber still in the bark), the math is different. The board foot formula above works for dimensional lumber, but for logs, scalers use the Doyle Rule, the Scribner Decimal C Rule, or the International 1/4-Inch Rule. These are empirical formulas that estimate how many board feet of usable lumber can be sawn from a given log, accounting for saw kerf, slab waste, and taper. This calculator focuses on lumber that has already been milled, which covers the needs of most woodworkers, contractors, and DIYers. If you need a log scaling tool, that is a different beast entirely.
How to calculate board feet.
Board footage measures lumber volume. One board foot is 1′ × 1′ × 1″.
Enter dimensions
Input thickness, width, and length. Toggle between Imperial and Metric seamlessly.
Set quantity and price
How many boards? What's the price per board foot? Results update instantly.
Build your cut list
Add multiple board sizes to a project cut list. Totals auto-calculate with waste margin.
Board Foot Formula
1 board foot = 144 in³. Metric values convert to inches and feet internally.
Frequently asked questions.
What is a board foot?
A board foot is a volume measurement used for lumber in the US and Canada. One board foot equals 12" × 12" × 1" — or 144 cubic inches. It is different from a linear foot (which only measures length) or a square foot (which measures area), because board feet account for thickness, width, and length all at once.
How do I manually calculate board feet?
The formula is: Thickness (in) × Width (in) × Length (ft) ÷ 12. For an 8-foot 2×4, that is 1.5 × 3.5 × 8 ÷ 12 = 3.5 board feet. A 10-foot 2×4 is 1.5 × 3.5 × 10 ÷ 12 = 4.375 board feet. The hard part is doing this over and over for every board in a project — that is why this calculator exists.
Why is a 2×4 not actually 2 inches by 4 inches?
The "2×4" is the nominal size — what the board was called before being dried and planed. After milling, the actual dimensions are 1.5" × 3.5". Same goes for 2×6 (actual: 1.5" × 5.5"), 4×4 (actual: 3.5" × 3.5"), and 1×6 (actual: 0.75" × 5.5"). This calculator uses actual dimensions in its presets so you do not have to remember the differences.
How much does lumber cost per board foot in 2026?
It varies wildly by species and region. Common construction lumber like pine or SPF runs about $1–$3 per board foot. Domestic hardwoods like oak, maple, and cherry range from $4–$10. Exotics like mahogany or teak can go $12–$25 or more. Prices also fluctuate with the market — check with your local supplier for current rates.
How do I convert linear feet to board feet?
You need to know the thickness and width too, since board feet measure volume. Take the thickness (in), multiply by width (in), multiply by linear length (ft), then divide by 12. A 10-foot 1×6 (0.75" × 5.5") is 0.75 × 5.5 × 10 ÷ 12 = 3.44 board feet. Our calculator does this automatically — just enter your dimensions.
What is a waste factor and why should I include one?
Waste factor accounts for lumber you will lose to offcuts, knots, mistakes, and off-by-one cuts. For framing, 5% is usually enough. For furniture or cabinetry with complex joinery, 10–20% is safer. This calculator has a waste slider so you can dial in the buffer you need without doing extra math.
Can I save my cut list and come back to it later?
Yes. Your cut list is saved in your browser automatically — no account needed. Close the tab, come back tomorrow, and everything is still there. This works because the data never leaves your machine. If you clear your browser data, the list will reset, so export anything important.
Is this calculator accurate for rough lumber?
It depends on the measurements you enter. If you are working with rough-sawn lumber that has not been surfaced, you need to measure the actual dimensions yourself after planing. Rough lumber is often sold by the nominal size before milling, and the actual volume changes once it is surfaced. Enter whatever dimensions you plan to work with and the calculator will be accurate.
What is the difference between a board foot and a square foot?
A square foot measures area (length × width). A board foot measures volume (length × width × thickness). For example, a 12" × 12" slab that is 1" thick is 1 square foot AND 1 board foot. The same slab at 2" thick is still 1 square foot, but now it is 2 board feet. Thickness is what separates the two.
Does the calculator work for metric measurements?
Yes. Toggle the unit switch and enter dimensions in millimeters for thickness, width, and length in meters. The calculator converts everything internally and shows results in both board feet and cubic meters. This is useful if you are working with imported lumber or European-sourced materials.
How many board feet does a 2x4x8 have?
An 8-foot 2×4 has 3.5 board feet (1.5 × 3.5 × 8 ÷ 12). A 2x4x10 has 4.375 BF. A 2x4x12 has 5.25 BF. These are common sizes used in framing, and the calculator has Quick Fill presets for them so you do not have to type the dimensions every time.
Why is my board foot calculation different from the lumber yard's?
Lumber yards sometimes round. They might charge for the nearest whole board foot, or they might include a waste surcharge on small orders. Some yards also use the nominal size instead of the actual size for softwood. If you are unsure, ask how they calculate — most yards are happy to explain.