{
  "id": "board-foot",
  "version": "7ba8929743c8",
  "status": "published",
  "name": "Board Foot Calculator",
  "question": "How many board feet is my lumber?",
  "summary": "Computes board feet (length × width × thickness ÷ 144 cubic inches) per board and for several boards, and the cost at a price per board foot.",
  "category": "construction",
  "url": "https://www.acalculator.org/construction/board-foot-calculator",
  "markdown": "https://www.acalculator.org/construction/board-foot-calculator.md",
  "kind": "function",
  "method": "board feet = length × width × thickness ÷ 144 in³ (length in feet × width in inches × thickness in inches ÷ 12)",
  "assumptions": [
    "One board foot is 144 cubic inches: a board 12 inches long, 12 inches wide and 1 inch thick.",
    "Use the size you pay for. Softwood lumber is often sold by its nominal size (a 2×4 is billed as 2 in × 4 in), while its actual size is smaller (1.5 in × 3.5 in).",
    "The cost is total board feet × price per board foot, with no waste allowance."
  ],
  "inputs": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "properties": {
      "l": {
        "title": "Length",
        "description": "The length of one board.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "length",
        "exclusiveMinimum": 0,
        "maximum": 1000
      },
      "w": {
        "title": "Width",
        "description": "The width of one board.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "length",
        "exclusiveMinimum": 0,
        "maximum": 100
      },
      "t": {
        "title": "Thickness",
        "description": "The thickness of one board.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "length",
        "exclusiveMinimum": 0,
        "maximum": 100
      },
      "quantity": {
        "title": "Number of boards",
        "description": "How many boards of this size.",
        "type": "integer",
        "minimum": 1,
        "maximum": 1000000
      },
      "price": {
        "title": "Price per board foot",
        "description": "What one board foot costs, to work out the total cost. Leave empty to skip the cost.",
        "type": "number",
        "x-unit": "USD",
        "minimum": 0,
        "maximum": 100000
      }
    }
  },
  "outputs": {
    "total": {
      "label": "Total board feet",
      "description": "Board feet for all the boards: board feet per board × number of boards.",
      "format": "number"
    },
    "each": {
      "label": "Board feet per board",
      "description": "Length × width × thickness of one board, divided by 144 cubic inches.",
      "format": "number"
    },
    "volume": {
      "label": "Volume",
      "description": "The total wood volume: 1 board foot is 1/12 of a cubic foot.",
      "format": "quantity",
      "unit": "ft3"
    },
    "cost": {
      "label": "Total cost",
      "description": "Total board feet × price per board foot.",
      "format": "money"
    }
  },
  "defaultAnswer": {
    "inputs": {
      "l": 2.4384,
      "w": 0.15239999999999998,
      "t": 0.0254,
      "quantity": 1
    },
    "outputs": {
      "total": 4,
      "each": 4,
      "volume": 0.009438948863999999
    },
    "text": "Boards of 8 ft × 6 in × 1 in, 1 in all, make 4 board feet."
  },
  "examples": [
    {
      "given": {
        "l": 2.4384,
        "w": 0.15239999999999998,
        "t": 0.0254,
        "quantity": 1
      },
      "expect": {
        "total": 4,
        "each": 4
      },
      "source": "hand calculation in content.mdx: 8 ft × 6 in × 1 in ÷ 12 = 4 board feet; Wikipedia, Board foot (a board foot is 144 cubic inches: 12 in × 12 in × 1 in). https://en.wikipedia.org/wiki/Board_foot"
    },
    {
      "given": {
        "l": 2.4384,
        "w": 0.254,
        "t": 0.03175,
        "quantity": 1
      },
      "expect": {
        "total": 8.333333333333334
      },
      "source": "hand calculation in content.mdx: 8 × 10 × 1.25 ÷ 12 = 8.33 board feet; Wikipedia, Board foot (a board foot is 144 cubic inches: 12 in × 12 in × 1 in). https://en.wikipedia.org/wiki/Board_foot"
    },
    {
      "given": {
        "l": 3.048,
        "w": 0.08889999999999999,
        "t": 0.038099999999999995,
        "quantity": 12,
        "price": 2.5
      },
      "expect": {
        "each": 4.375,
        "total": 52.5,
        "cost": 131.25
      },
      "source": "hand calculation in content.mdx: 10 × 3.5 × 1.5 ÷ 12 = 4.375; × 12 = 52.5; × $2.50 = $131.25; Wikipedia, Board foot (a board foot is 144 cubic inches: 12 in × 12 in × 1 in). https://en.wikipedia.org/wiki/Board_foot"
    }
  ],
  "sources": [
    "Wikipedia, Board foot (a board foot is 144 cubic inches: 12 in × 12 in × 1 in). https://en.wikipedia.org/wiki/Board_foot"
  ],
  "related": [],
  "changelog": [
    {
      "date": "2026-09-29",
      "note": "Worked examples name a published reference for their rule."
    }
  ]
}