# Board Foot Calculator Free board foot calculator: enter thickness, width, length, and number of pieces to get board feet, linear feet, and the cost at your lumber price. Calculator page: (updated 2026-10-06). This Markdown version shows the default example; enter your own dimensions on the page. **Answer:** 10 pieces of 2 × 6 in × 8 ft lumber is 80 board feet (8 board feet each). ## How to use this board foot calculator 1. Enter the thickness and width in inches. For standard softwood lumber, use the nominal size (2 and 6 for a 2 × 6). 2. Enter the length in feet or inches. 3. Enter how many pieces of that size you need. 4. Optionally, enter your lumber yard's price per board foot to see a total. 5. For a mixed order, run each size separately and add the board feet. ## How to calculate board feet: the formula, shown A board foot is the unit lumber is sold and tallied in. The American Softwood Lumber Standard (PS 20) defines it: multiply the **nominal thickness in inches** by the **nominal width in feet** by the **length in feet**. With width in inches, that is thickness × width × length ÷ 12. One board foot is the same as a piece 1 in thick, 12 in wide, and 1 ft long. **Default example.** Ten 2 × 6 boards, 8 ft long, using nominal sizes. **Default example arithmetic** ```text Per piece = 2 in × 6 in × 8 ft ÷ 12 = 8 bd ft Total = 8 bd ft × 10 pieces = 80 bd ft Linear feet = 8 ft × 10 = 80 ft Cost = total bd ft × your price per bd ft (enter a price to see it) ``` PS 20 notes that a board foot “is not a well-defined unit of volume”: because it is based on nominal dimensions, it does not equal the wood's actual dressed volume. Use it for buying and pricing, not to calculate weight. ![Diagram of one 2 by 6 inch board, 8 ft long, with the thickness, width and length a board foot calculation uses labeled](https://www.howmanyyardsdoineed.com/images/board-foot-calculator/board-foot-dimensions-diagram.png) The default example board with its thickness, width, and length labeled (not to scale). ## Board feet chart for common lumber sizes Board feet per piece for common nominal lumber sizes and lengths, computed with the PS 20 formula. **Board feet per piece by nominal size and length** | Nominal size | Per linear ft | 8 ft | 10 ft | 12 ft | 16 ft | | --- | --- | --- | --- | --- | --- | | 1 × 4 | 0.333 | 2.67 | 3.33 | 4 | 5.33 | | 1 × 6 | 0.5 | 4 | 5 | 6 | 8 | | 1 × 8 | 0.667 | 5.33 | 6.67 | 8 | 10.67 | | 2 × 4 | 0.667 | 5.33 | 6.67 | 8 | 10.67 | | 2 × 6 | 1 | 8 | 10 | 12 | 16 | | 2 × 8 | 1.333 | 10.67 | 13.33 | 16 | 21.33 | | 2 × 10 | 1.667 | 13.33 | 16.67 | 20 | 26.67 | | 2 × 12 | 2 | 16 | 20 | 24 | 32 | | 4 × 4 | 1.333 | 10.67 | 13.33 | 16 | 21.33 | | 6 × 6 | 3 | 24 | 30 | 36 | 48 | Board feet per linear foot = thickness × width ÷ 12. Multiply by the number of pieces for a total. ## Quick answers: board feet in common lumber sizes Each answer is computed with the same formula as the calculator, using its default settings unless the question says otherwise. ### How many board feet are in a 2x4x12? A 2 × 4 in board 12 ft long is 8 board feet, using nominal sizes as lumber is sold. ### How many board feet in a 2x8x14? A 2 × 8 in board 14 ft long is 18.667 board feet, using nominal sizes as lumber is sold. ### How many board feet are in a 2x10x16? A 2 × 10 in board 16 ft long is 26.667 board feet, using nominal sizes as lumber is sold. ### How many board feet is a 2x12x20? A 2 × 12 in board 20 ft long is 40 board feet, using nominal sizes as lumber is sold. ### How many board feet are in a 4x4x10? A 4 × 4 in board 10 ft long is 13.333 board feet, using nominal sizes as lumber is sold. ### How many board feet is a 6x6x12 post? A 6 × 6 in board 12 ft long is 36 board feet, using nominal sizes as lumber is sold. ### How many board feet are in a 1x6x8? A 1 × 6 in board 8 ft long is 4 board feet, using nominal sizes as lumber is sold. ### How many board feet are in 25 2x6x12 boards? A stack of 25 pieces of 2 × 6 in lumber 12 ft long is 300 board feet, at 12 board feet each and 300 linear feet in all. ### How many board feet are in 100 2x4x8 boards? A stack of 100 pieces of 2 × 4 in lumber 8 ft long is 533.33 board feet, at 5.333 board feet each and 800 linear feet in all. ## Buying lumber by the board foot The default ten 2 × 6 × 8 ft boards come to 80 board feet. Hardwood and specialty lumber is usually priced per board foot; dimensional lumber at home centers is usually priced per piece. Board feet let you compare the two. - Large orders are often quoted per thousand board feet (MBF). Divide total board feet by 1,000. - Add extra pieces for defects, cuts, and mistakes; how many depends on the grade and the job. - For deck surfaces, the [deck calculator](https://www.howmanyyardsdoineed.com/deck-calculator/) counts boards from the deck size, board width, and gap. ## Nominal vs. actual lumber sizes A “2 × 6” is a nominal size. After drying and planing, PS 20 lists the minimum dressed (dry) size of a nominal 6 in width as 5-1/2 in, and a nominal 2 in thickness as 1-1/2 in. Board feet for standard softwood lumber are still figured on the nominal size, which is why the calculator asks for nominal dimensions. For actual sizes of other common lumber, see the [nominal vs. actual lumber size chart](https://www.howmanyyardsdoineed.com/guides/nominal-vs-actual-lumber-sizes/). ### Rough-sawn and nonstandard lumber For lumber finished to nonstandard sizes, PS 20 says it is tallied by board measure using the rough or nominal size it was made from. Hardwood and rough-sawn sellers may use their own conventions, so ask how your yard measures before comparing prices. ## Tips for estimating lumber - Check whether your supplier prices by the board foot, the linear foot, or the piece before comparing quotes. - Board feet don't tell you weight. Wood density varies by species and moisture. - When ordering a mixed list, write each size and length on its own line, then total the board feet. - For trim and boards sold by length, the linear-feet figure is often what you need. ## Board foot calculator FAQ ### How do I calculate board feet? Multiply thickness in inches by width in inches by length in feet, then divide by 12. The American Softwood Lumber Standard (PS 20) states it as nominal thickness in inches × nominal width in feet × length in feet, which is the same thing. ### How many board feet are in a 2x4x8? Using nominal sizes, 2 × 4 × 8 ÷ 12 = 5.333 board feet. ### How many board feet are in a 2x6x10? 2 × 6 × 10 ÷ 12 = 10 board feet per piece. ### What is one board foot? The amount of lumber in a piece 1 inch thick, 12 inches wide, and 1 foot long, measured by nominal size. PS 20 notes it is not a well-defined unit of volume because it uses nominal rather than actual dimensions. ### Do I use nominal or actual dimensions for board feet? For standard softwood lumber, nominal dimensions: PS 20 defines board measure using nominal thickness and width. A 2 × 6 counts as 2 by 6 even though it measures smaller after dressing. ### What does MBF mean? Thousand board feet. Bulk lumber prices are often quoted per MBF; divide your total board feet by 1,000 to compare. ### How do I find the cost of lumber by the board foot? Multiply total board feet by the price per board foot. Enter your supplier's price in the calculator to see the total. ### What is the difference between board feet and linear feet? Linear feet measure length only. Board feet account for thickness and width too, so a 2 × 12 has three times the board feet of a 2 × 4 of the same length. ## Related calculators and guides ### Calculators - [Deck Calculator](https://www.howmanyyardsdoineed.com/deck-calculator/) — Decking board count from deck size, actual board width, gap, and board length, with the cutting assumptions shown. - [Square Footage Calculator](https://www.howmanyyardsdoineed.com/square-footage-calculator/) — Total area in square feet, square meters, square yards, and acres from rectangles, triangles, circles, and trapezoids, minus cut-outs. - [Roof Pitch Calculator](https://www.howmanyyardsdoineed.com/roof-pitch-calculator/) — Pitch as x/12, roof angle in degrees, slope percentage, and the sloped length for a given horizontal run. ### Guides - [Nominal vs. Actual Lumber Sizes](https://www.howmanyyardsdoineed.com/guides/nominal-vs-actual-lumber-sizes/) — A chart of real lumber dimensions from the national standard, dry versus green sizes, lengths, and board feet. - [How to Plan a Bulk Material Delivery](https://www.howmanyyardsdoineed.com/guides/planning-material-delivery/) — Rounding to supplier increments, questions to ask, and a checklist before bulk material arrives. ## Sources - [Voluntary Product Standard PS 20-25, American Softwood Lumber Standard: definition of board measure](https://www.nist.gov/system/files/documents/2024/12/11/PS%2020-25%20Final.pdf) — National Institute of Standards and Technology. Used for: Board feet = nominal thickness (in) × nominal width (ft) × length (ft). Checked 2026-10-05. **Estimate only.** Results are planning estimates computed from the numbers you enter. They are not engineering, structural, or code advice. Confirm quantities, product yields, and installation requirements with your supplier, the product label, and your local building authority before you order or build.