Board Foot Calculator – Lumber Volume and Cost
Our free board foot calculator turns your cut list into board feet and a total price. Add every board with its thickness, width, length, and the price per board foot, and the calculator works out the board feet per piece and in total, plus linear feet, cubic feet, cubic meters, and the cost. It knows nominal sizes like 2×4, hardwood quarters like 4/4 and 8/4, and you can print or copy the list for the lumberyard.
How to Use the Board Foot Calculator
- Enter the first board. Type the number of pieces, the thickness and width in inches, and the length in feet. You can also type the length in inches with the inch mark, for example 96 with the inch mark for an 8 foot board.
- Use the quick sizes. The “Lumber” buttons fill in 1×4 to 6×6 and mark the row as a nominal size. The “Hardwood” buttons set the thickness in quarters, from 4/4 to 12/4.
- Add the price. Type the price per board foot from the lumberyard. Each row can have its own price, so walnut and poplar can sit in the same list.
- Add more boards. Tap “Add another board” for every size or species in your cut list. You can name each row, for example “Oak top” or “Pine legs.”
- Choose nominal or actual. For rows marked as nominal size, pick whether the board feet come from the nominal size (what most lumberyards use) or the actual dressed size.
- Add extra for waste. Rough lumber has knots, checks, and ends you cut off. The quick buttons add 10, 15, 20, or 30%.
- Copy or print. The full list with every board, the totals, and your settings goes to the clipboard or prints on US Letter or A4.
What Is a Board Foot?
A board foot is a unit of volume for lumber. It is a piece 1 inch thick, 12 inches wide, and 12 inches long, which equals 144 cubic inches. Twelve board feet make one cubic foot. Hardwood lumberyards sell almost everything by the board foot, because boards come in random widths and lengths, and volume is the only fair way to price them.
The Board Foot Formula
Board feet = thickness (in) × width (in) × length (ft) ÷ 12
If you measure the length in inches too, divide by 144 instead: thickness × width × length (all in inches) ÷ 144. The result is the same.
Example: Ten 2×4 Studs
A 2×4 that is 8 feet long has 2 × 4 × 8 ÷ 12 = 5.33 board feet when you count the nominal size. Ten of them are 53.3 board feet. If you count the actual size of 1 1/2 × 3 1/2 inches instead, each stud is 1.5 × 3.5 × 8 ÷ 12 = 3.5 board feet, and ten are 35 board feet. The difference is why it pays to ask your supplier which number they use.
Example: Hardwood for a Small Table
Three walnut boards, 4/4 thick (1 inch), 6 inches wide, and 8 feet long, are 1 × 6 × 8 ÷ 12 = 4 board feet each, or 12 board feet together. At $6.50 per board foot, that is $78. With 15% extra for defects and offcuts, plan on about 13.8 board feet and $89.70.
Nominal vs. Actual Lumber Sizes
Softwood lumber from home centers is named by its nominal size. A 2×4 starts out close to 2 × 4 inches when it is sawn, but drying and planing make it smaller. The actual dressed sizes follow the American Softwood Lumber Standard (PS 20):
| Nominal size | Actual size | Board feet per 8 ft (nominal) | Board feet per 8 ft (actual) |
|---|---|---|---|
| 1×4 | 3/4 × 3 1/2 in | 2.67 | 1.75 |
| 1×6 | 3/4 × 5 1/2 in | 4.00 | 2.75 |
| 2×4 | 1 1/2 × 3 1/2 in | 5.33 | 3.50 |
| 2×6 | 1 1/2 × 5 1/2 in | 8.00 | 5.50 |
| 2×8 | 1 1/2 × 7 1/4 in | 10.67 | 7.25 |
| 2×10 | 1 1/2 × 9 1/4 in | 13.33 | 9.25 |
| 2×12 | 1 1/2 × 11 1/4 in | 16.00 | 11.25 |
| 4×4 | 3 1/2 × 3 1/2 in | 10.67 | 8.17 |
The rule behind the table: boards thinner than 2 inches lose 1/4 inch in thickness, thicker ones lose 1/2 inch. Widths under 8 inches lose 1/2 inch, and widths of 8 inches and more lose 3/4 inch. The calculator uses exactly these rules when you switch to “Actual size (dressed).”
Most lumberyards that sell softwood by the board foot or by the thousand board feet (MBF) count the nominal size. That is why the calculator starts with “Nominal size (lumberyard standard).” Use “Actual size (dressed)” when you want to know how much wood you really get, for example to compare a price per piece with a price per board foot.
Hardwood Thickness in Quarters
Hardwood is sold rough or skip-planed, and its thickness is given in quarters of an inch. A 4/4 board (“four quarter”) is about 1 inch thick, 5/4 is 1 1/4 inches, 6/4 is 1 1/2 inches, and 8/4 is 2 inches. The board feet come from this rough thickness, not from the thinner size after you plane it. A 4/4 board usually ends up around 3/4 inch thick after surfacing, so buy thick enough for your final size.
For hardwood, do not mark the row as nominal. Enter the quarter thickness and the measured width and length, as the “Hardwood” buttons do. Many yards measure the width to the nearest inch and the length to the nearest foot, so a list can differ a little from the yard’s tally.
How Much Extra Lumber Should You Buy?
A cut list shows the parts you need, not the wood you have to buy. Rough boards have checks at the ends, knots, sapwood, and a bit of twist, and every cut takes a saw kerf. Common rules of thumb:
- Construction lumber: 5 to 10% extra for bad pieces and offcuts.
- Furniture from rough hardwood: 15 to 30%, more for figured wood or when the grain has to match.
- Plywood and sheet goods: plan on a cutting diagram instead, because they are sold by the sheet, not by the board foot.
If you are new to buying hardwood, our guide on where to buy wood compares lumberyards, online shops, and home centers. If you do not own a table saw, read about places that will cut wood for you.
Price per Board Foot, Linear Foot, and Piece
Lumber prices come in three forms, and the calculator helps you compare them:
- Per board foot: common for hardwood. Enter it directly in each row.
- Per linear foot: common for trim, moldings, and some boards. Divide the price per linear foot by the board feet in one foot of the board. A 1×6 has 0.5 board feet per foot, so $2.00 per linear foot equals $4.00 per board foot.
- Per piece: common for studs and dimensional lumber. Divide the piece price by the board feet of one piece. An 8 ft 2×4 at $4.00 is $0.75 per nominal board foot.
Prices per thousand board feet (MBF) are simply divided by 1,000: $650 per MBF is $0.65 per board foot. Wood prices change often and vary by species, grade, and region, so always use the prices from your own supplier. If you are curious why some species cost so much more, read about the most expensive woods.
Tips for Your Cut List
- Know your species. Poplar, pine, oak, and walnut differ a lot in price and in how they work. Compare pine vs. poplar and learn how to identify wood before you shop.
- Plan the joints first. Tenons, dados, and lap joints add length or width to some parts. Our overview of types of wood joints helps you add them to the list.
- Consider sheet goods. For cabinet sides and shelves, plywood or MDF may be cheaper and more stable. See MDF vs. particle board and what engineered wood is.
- Bring the printout. A printed list with every board, size, and price makes it easier to compare stacks at the yard and to check the bill.
For project ideas that turn a few board feet into something useful, browse our small woodworking projects or plan your own DIY wood countertops.
Metric Units and Privacy
Switch to metric to enter thickness and width in millimeters and length in meters. The calculator still shows board feet and adds cubic meters, which is how lumber is priced in most of the world. In metric mode, the price field is per cubic meter.
Everything runs in your browser. There is no sign-up, and nothing you enter leaves your device. The results are estimates for planning, and the tally of your lumberyard is what you pay for.
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Frequently Asked Questions
How Do You Calculate Board Feet?
Multiply the thickness in inches by the width in inches and the length in feet, then divide by 12. A board 1 inch thick, 6 inches wide, and 8 feet long has 4 board feet.
How Many Board Feet Are in a 2x4x8?
With the nominal size, a 2×4 that is 8 feet long has 5.33 board feet. With the actual size of 1 1/2 × 3 1/2 inches, it has 3.5 board feet.
Do You Use Nominal or Actual Size for Board Feet?
Lumberyards usually count softwood by its nominal size. Rough hardwood is counted by its rough thickness in quarters, such as 4/4 or 8/4, and its measured width and length. Ask your supplier when you compare prices.
How Many Board Feet Are in a Cubic Foot?
There are 12 board feet in a cubic foot, because one board foot is 144 cubic inches and a cubic foot is 1,728 cubic inches.
How Do I Convert a Price per Linear Foot to a Price per Board Foot?
Divide the price per linear foot by the board feet in one linear foot. For a 1×6, one linear foot is 0.5 board feet, so $3.00 per linear foot is $6.00 per board foot.
What Does 4/4 Mean in Lumber?
It means four quarters of an inch, so about 1 inch of rough thickness. 5/4 is 1 1/4 inches, 6/4 is 1 1/2 inches, and 8/4 is 2 inches.
How Many Board Feet Are in a Cubic Meter?
One cubic meter has about 423.8 board feet. One board foot is 0.00236 cubic meters.
Is the Board Foot Calculator Free?
Yes. It is free, needs no account, handles as many boards as you like, and lets you copy or print the list.
Robert Thompson has worked as a self-employed carpenter for over 15 years. He lives with his family in Billings, Montana, where he also successfully operates his business as a woodworker. His main business is the complete interior construction of buildings. He is also passionate about creating high-quality wood furniture with epoxy and other items made from burl wood. Besides the woodwork, Robert is also a skilled DIY professional for all kinds of materials. He always has a solution ready for every craft and construction challenge. Originally, Robert studied civil engineering and has advanced degrees in carpentry and business management. Robert has been working for Craft Art since 2020 and enriches the blog with his immense knowledge and skills in the field of woodworking and home improvement. He writes the articles about DIY and Repair.
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