--- title: "What is a board foot, and how to calculate board feet" description: "A board foot is 144 cubic inches of lumber, 12\" × 12\" × 1\". How to calculate board feet from nominal sizes, with a printable chart for 1x4 to 6x6." canonical: https://klmlabs.app/construction-calculator/board-feet/ updated: 2026-11-07 --- # How to calculate board feet A board foot is 144 cubic inches of lumber: 12" × 12" × 1". Multiply thickness × width in inches by the length in feet, then divide by 12. Download the printable chart (PDF, US Letter, 1 page, 29 KB): https://klmlabs.app/construction-calculator/charts/board-feet.pdf. Every number is worked out by Construction Calculator 1.1.1's own formulas. ## Board feet by nominal size and length | Nominal size | Per foot | 8 ft | 10 ft | 12 ft | 14 ft | 16 ft | |---|---:|---:|---:|---:|---:|---:| | 1x4 | 0.33 | 2.67 | 3.33 | 4 | 4.67 | 5.33 | | 1x6 | 0.5 | 4 | 5 | 6 | 7 | 8 | | 1x8 | 0.67 | 5.33 | 6.67 | 8 | 9.33 | 10.67 | | 1x10 | 0.83 | 6.67 | 8.33 | 10 | 11.67 | 13.33 | | 1x12 | 1 | 8 | 10 | 12 | 14 | 16 | | 2x4 | 0.67 | 5.33 | 6.67 | 8 | 9.33 | 10.67 | | 2x6 | 1 | 8 | 10 | 12 | 14 | 16 | | 2x8 | 1.33 | 10.67 | 13.33 | 16 | 18.67 | 21.33 | | 2x10 | 1.67 | 13.33 | 16.67 | 20 | 23.33 | 26.67 | | 2x12 | 2 | 16 | 20 | 24 | 28 | 32 | | 4x4 | 1.33 | 10.67 | 13.33 | 16 | 18.67 | 21.33 | | 4x6 | 2 | 16 | 20 | 24 | 28 | 32 | | 6x6 | 3 | 24 | 30 | 36 | 42 | 48 | By nominal size: a 2x4 counts as 2" × 4". To 2 decimal places. ## Board feet per linear foot by thickness and width | Thickness | 4" wide | 6" wide | 8" wide | 10" wide | 12" wide | |---|---:|---:|---:|---:|---:| | 1/2" | 0.33 | 0.5 | 0.67 | 0.83 | 1 | | 3/4" | 0.33 | 0.5 | 0.67 | 0.83 | 1 | | 4/4 (1") | 0.33 | 0.5 | 0.67 | 0.83 | 1 | | 5/4 (1-1/4") | 0.42 | 0.63 | 0.83 | 1.04 | 1.25 | | 6/4 (1-1/2") | 0.5 | 0.75 | 1 | 1.25 | 1.5 | | 8/4 (2") | 0.67 | 1 | 1.33 | 1.67 | 2 | Boards under 1" count as 1", so the 1/2" and 3/4" rows match 4/4. Some yards count the fraction: ask yours. ## How many board feet are in a 2x4x10? 6.67 board feet: 2 × 4 × 10 ÷ 12. A 2x4x8 is 5.33 board feet, a 2x6x8 is 8, and a 4x4x8 is 10.67. If the length is in inches too, divide by 144 instead. ## Do I use the real size or the nominal size? The nominal size: a 2x4 counts as 2" × 4", though a dry one is really 1-1/2" × 3-1/2". So a 2x4x8 is 5.33 board feet on the bill, or 3.5 board feet of actual volume. ## What do 4/4 and 5/4 mean? Hardwood is sold in quarters of an inch: 4/4 is 1", 5/4 is 1-1/4", 6/4 is 1-1/2" and 8/4 is 2". A 5/4 board 6" wide holds 0.63 board feet per foot. ## How are board feet different from square and linear feet? A board foot is volume, a square foot is area, a linear foot is length. A 2x6 holds exactly 1 board foot per linear foot, so a 2x6 that is 14' long is 14 board feet. ## How do I price lumber by the board foot? Multiply board feet by the price per board foot. Ten 2x4x8s are 53.33 board feet; at $1.25 a board foot that is $66.67. ## Work out your own with Construction Calculator - Board feet for one piece or a whole stack - Add a price per board foot to get the cost - Each tool opens a short guide with a worked example Download Construction Calculator on the App Store: https://apps.apple.com/us/app/fraction-feet-inch-calculator/id6816445977 Free to download, with in-app purchases. Every feature, the calculator included, needs the free trial or a purchase: Yearly US$9.99 a year with a 7-day free trial for eligible new subscribers, or Lifetime US$19.99 paid once (US prices). iPhone and iPad, iOS 17.0 or later. All the facts: https://klmlabs.app/construction-calculator/ ## The facts this page states, with sources As KLM Labs' fact record words them; the page may put them in its own words. Construction Calculator's facts page: https://klmlabs.app/construction-calculator/ - 11 tools, from stairs, roof pitch and rafters to concrete, board feet and miters. (Source: [Apple's app lookup](https://itunes.apple.com/lookup?id=6816445977&country=us).) - Every tool opens a short guide with a worked example. (Source: [Apple's app lookup](https://itunes.apple.com/lookup?id=6816445977&country=us).) - Works offline once your trial or purchase is active. (Source: [Apple's app lookup](https://itunes.apple.com/lookup?id=6816445977&country=us).) - Board foot: 12 in. long, 12 in. wide and 1 in. thick or its cubic equivalent; figured on nominal thickness and width and actual length; lumber under 1 in. nominal thickness is calculated as 1 in. (Source: https://research.fs.usda.gov/download/treesearch/62200.pdf (USDA Forest Products Laboratory, Wood Handbook FPL-GTR-282, 2021, glossary; read 2026-11-06).) - PS 20-20 section 2.2: board feet = nominal thickness in inches or fraction of an inch × nominal width in feet × length in feet; Table 3: a dry 2x4 is dressed to 1-1/2 in. × 3-1/2 in. (Source: https://www.nist.gov/system/files/documents/2019/12/11/PS%2020-20%20final%20WERB%20approved.pdf (NIST PS 20-20, American Softwood Lumber Standard; read 2026-11-06).) ## More construction charts - [How many bags of concrete in a yard?](https://klmlabs.app/construction-calculator/concrete-bags-per-yard/): About 45 bags of 80 lb concrete make a cubic yard, 60 of 60 lb, 90 of 40 lb. A slab chart in yards and bags with 10% waste, as a free printable PDF. - [How to calculate square footage from inches and fractions](https://klmlabs.app/construction-calculator/square-feet-from-feet-and-inches/): Multiply length × width in inches and divide by 144 for square feet. Worked examples with feet, inches and fractions, done exactly, and a printable chart. - [Fraction to decimal chart: inches, millimeters and feet](https://klmlabs.app/construction-calculator/fraction-decimal-inch-chart/): A fraction to decimal chart for every 64th of an inch, with millimeters and decimal feet, plus inches to decimal feet. Free printable PDF, US Letter. - [Roof pitch chart: degrees, slope and rafter length](https://klmlabs.app/construction-calculator/roof-pitch-chart/): A roof pitch chart from 1/12 to 24/12: the angle in degrees, slope percent, plumb and seat cuts, and rafter length per foot of run. Free printable PDF. - [Stair rise and run code: 7-3/4" risers, 10" treads](https://klmlabs.app/construction-calculator/stair-rise-and-run/): The 2021 IRC limits for stair risers (7-3/4" max) and treads (10" min), the 7-11 rule, and worked stair layouts for rises from 2' to 10'. Free PDF. - [Crown molding angles chart: miter and bevel settings](https://klmlabs.app/construction-calculator/crown-molding-angles/): Miter and bevel settings for 52/38 and 45/45 crown molding cut flat on a compound miter saw, for wall corners from 60° to 150°. Free printable chart. All 7 construction charts: https://klmlabs.app/construction-calculator/guides/ ## Sources 1. [USDA Forest Products Laboratory: Wood Handbook, FPL-GTR-282 (2021), glossary, “Board foot”](https://research.fs.usda.gov/download/treesearch/62200.pdf) 2. [NIST: Voluntary Product Standard PS 20-20, American Softwood Lumber Standard (board measure, section 2.2; dressed sizes, Table 3)](https://www.nist.gov/system/files/documents/2019/12/11/PS%2020-20%20final%20WERB%20approved.pdf) 3. [Fraction Feet Inch Calculator (Construction Calculator) on the App Store](https://apps.apple.com/us/app/fraction-feet-inch-calculator/id6816445977) Last updated November 7, 2026.