Enrichment · Arts and Creativity · Woodshop

Know the board feet
before you stand
at the lumber rack.

Type each part of the project with its count, thickness, width and length. The calculator gives the board feet of every line and the whole list, adds waste, and prices it.

Price the cut listWhat you get

The board foot calculator

The worked example is a made-up red oak bookshelf with 20% waste at $7.50 a board foot. Nothing you type leaves this browser.

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What you get

Enrichment · Arts & CreativityFree

What you finish with
Board feet for each line and the whole cut list, the amount to buy with waste, and the cost. It prints as a summary and downloads as a spreadsheet.
Who it is for
Woodworking and shop students, career and technical education classes, and families planning a project at home.
Format
Browser calculator for a phone, tablet or computer, by touch or keyboard. Up to 40 lines. Prints a summary; downloads a spreadsheet (.csv); export and import a file.
Access
Free. No account, no sign-in and nothing to install. Everything you type stays in this browser; nothing is sent to Caveat.
Where it lives
The Arts & Creativity space in Caveat Enrichment.
Support
Questions, a correction or a request: team@caveatacademic.com.

How to use it

  1. Name the project and species, and set the waste allowance.
  2. Add each part with its count, thickness, width and length.
  3. Type the yard's price per board foot to see the cost.
  4. Read which part uses the most wood; a narrower or shorter part there saves the most.
  5. Print the list and take it to the yard.

Price the cut list

How board feet are worked out

A volume, in a unit the lumber trade uses.

The worked example: the bookshelf topOne board1″ × 12″ × 1 ft144 cubic inchesThe top, 5/41.25 × 12 × 3.5inches × inches × feet÷ 124.38 BF52.5 ÷ 12Whole list35.3 BF29.38 × 1.20 wasteThe worked example: the bookshelf topOne board1″ × 12″ × 1 ft144 cubic inchesThe top, 5/41.25 × 12 × 3.5inches × inches × feet÷ 124.38 BF52.5 ÷ 12Whole list35.3 BF29.38 × 1.20 waste
A board foot is a volume. Mixing inches and feet is what makes the divisor 12 rather than 144.

The arithmetic

A board foot is the wood in a board 1 inch thick, 12 inches wide and 1 foot long: 144 cubic inches. With thickness and width in inches and length in feet, board feet are thickness × width × length ÷ 12, times the count. The waste allowance multiplies the total by (1 + waste ÷ 100).

Nominal sizes

Rough hardwood is sold in quarters of an inch of thickness: 4/4 is 1 inch, 5/4 is 1¼, 8/4 is 2. It is priced on that nominal size even though it planes thinner. Construction lumber is named nominally too (a 2×4 is about 1½ × 3½ inches) and is usually sold by the piece, but its board feet are counted on the nominal 2 and 4.

Sources

  1. U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. Wood Handbook: Wood as an Engineering Material (FPL-GTR-282), lumber measurement and nominal sizes.
  2. National Hardwood Lumber Association. Rules for the Measurement and Inspection of Hardwood and Cypress: board foot and thickness in quarters (nhla.com).
  3. National Institute of Standards and Technology. Voluntary Product Standard PS 20, American Softwood Lumber Standard: nominal and dressed sizes.
  4. National Institute of Standards and Technology. Handbook 130, Uniform Laws and Regulations: method of sale of lumber by board foot.

The worked example is made up. Prices vary by species, grade and yard. Your cut list stays in this browser. Support: team@caveatacademic.com.