{
  "id": "asphalt",
  "version": "18419a603fb0",
  "status": "published",
  "name": "Asphalt Calculator",
  "question": "How many tons of asphalt do I need?",
  "summary": "Computes the tons of hot-mix asphalt for a driveway, parking lot or road from its area, compacted thickness and compacted density, with a waste allowance and a cost.",
  "category": "construction",
  "url": "https://www.acalculator.org/construction/asphalt-calculator",
  "markdown": "https://www.acalculator.org/construction/asphalt-calculator.md",
  "kind": "function",
  "method": "tons = area × compacted thickness × compacted density × (1 + waste ÷ 100) ÷ 2,000 lb",
  "assumptions": [
    "The thickness is the compacted (finished) thickness, and the density is the compacted density, so no loose-to-compacted factor is applied.",
    "With no density typed, the compacted density is Gmm × (1 − air voids ÷ 100) × 1,000 kg/m³ when Gmm is given, else a typical 2,360 kg/m³ (147.3 lb/ft³).",
    "Tons are US short tons of 2,000 lb; tonnes are metric tonnes of 1,000 kg.",
    "The cost is tons × price per ton, plus a flat delivery cost."
  ],
  "inputs": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "properties": {
      "geometryMethod": {
        "title": "Area",
        "description": "Whether you know the length and width or the total area.",
        "type": "string",
        "enum": [
          "simple",
          "direct"
        ]
      },
      "len": {
        "title": "Length",
        "description": "The length of the area to pave.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "length",
        "exclusiveMinimum": 0,
        "maximum": 1000000
      },
      "wid": {
        "title": "Width",
        "description": "The width of the area to pave.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "length",
        "exclusiveMinimum": 0,
        "maximum": 100000
      },
      "area": {
        "title": "Total area",
        "description": "The area to pave.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "area",
        "exclusiveMinimum": 0,
        "maximum": 1000000000
      },
      "thick": {
        "title": "Compacted thickness",
        "description": "The finished thickness of the asphalt after rolling.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "length",
        "exclusiveMinimum": 0,
        "maximum": 2
      },
      "wasteFactor": {
        "title": "Waste allowance",
        "description": "Extra asphalt for waste and uneven base, as a percent of the weight.",
        "type": "number",
        "x-unit": "percent",
        "minimum": 0,
        "maximum": 100
      },
      "density": {
        "title": "Compacted density",
        "description": "The density of the compacted asphalt. Leave empty to use Gmm and air voids, or the typical 2,360 kg/m³ (147.3 lb/ft³).",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "density",
        "exclusiveMinimum": 0,
        "maximum": 5000
      },
      "gmm": {
        "title": "Maximum specific gravity (Gmm)",
        "description": "The theoretical maximum specific gravity of the mix, from the mix design. Used with the air voids when no density is typed.",
        "type": "number",
        "minimum": 1,
        "maximum": 4
      },
      "airVoids": {
        "title": "Air voids",
        "description": "The air voids in the compacted mat, as a percent of its volume. Used with Gmm.",
        "type": "number",
        "x-unit": "percent",
        "minimum": 0,
        "maximum": 30
      },
      "price": {
        "title": "Price per ton",
        "description": "The price of one US ton (2,000 lb) of asphalt. Leave empty to skip the cost.",
        "type": "number",
        "x-unit": "USD",
        "minimum": 0,
        "maximum": 100000
      },
      "delivery": {
        "title": "Delivery cost",
        "description": "A flat trucking or delivery charge added to the material cost.",
        "type": "number",
        "x-unit": "USD",
        "minimum": 0,
        "maximum": 10000000
      }
    }
  },
  "outputs": {
    "tons": {
      "label": "Asphalt to order",
      "description": "The weight in US short tons: area × compacted thickness × density × (1 + waste ÷ 100).",
      "format": "quantity",
      "unit": "ton"
    },
    "tonnes": {
      "label": "Metric tonnes",
      "description": "The same weight in metric tonnes (1,000 kg).",
      "format": "quantity",
      "unit": "t"
    },
    "area": {
      "label": "Area",
      "description": "The area paved.",
      "format": "quantity",
      "unit": "ft2"
    },
    "volume": {
      "label": "Compacted volume",
      "description": "Area × compacted thickness, before the waste allowance.",
      "format": "quantity",
      "unit": "yd3"
    },
    "densityUsed": {
      "label": "Density used",
      "description": "The compacted density used: the one typed, else Gmm × (1 − air voids) × 1,000 kg/m³, else 2,360 kg/m³.",
      "format": "quantity",
      "unit": "lb-ft3"
    },
    "cost": {
      "label": "Estimated cost",
      "description": "Tons × price per ton, plus the delivery cost.",
      "format": "money"
    }
  },
  "defaultAnswer": {
    "inputs": {
      "geometryMethod": "simple",
      "len": 30.48,
      "wid": 6.096,
      "area": 185.80608,
      "thick": 0.07619999999999999,
      "wasteFactor": 0,
      "airVoids": 4
    },
    "outputs": {
      "tons": 33413.878978559995,
      "tonnes": 33413.878978559995,
      "area": 185.80608,
      "volume": 14.158423295999999,
      "densityUsed": 2360
    },
    "text": "2,000 ft² of asphalt 3 in thick needs 36.83 tons."
  },
  "examples": [
    {
      "given": {
        "geometryMethod": "simple",
        "len": 30.48,
        "wid": 6.096,
        "thick": 0.07619999999999999,
        "wasteFactor": 0,
        "airVoids": 4
      },
      "expect": {
        "tons": 33413.878978559995,
        "volume": 14.158423296000002
      },
      "source": "hand calculation in content.mdx: 2,000 ft² × 0.25 ft = 500 ft³ = 14.158 m³; × 2,360 kg/m³ = 33,413 kg = 36.83 US tons; NIST Handbook 44 (2026), Appendix C, General Tables of Units of Measurement: 1 cubic yard = 27 cubic feet, 1 short ton = 2,000 pounds. https://www.nist.gov/document/2026-nist-handbook-44-appendix-c"
    },
    {
      "given": {
        "geometryMethod": "simple",
        "len": 30.48,
        "wid": 6.096,
        "thick": 0.07619999999999999,
        "wasteFactor": 5,
        "gmm": 2.45,
        "airVoids": 4,
        "price": 110
      },
      "expect": {
        "densityUsed": 2352,
        "tons": 34965.642171801606,
        "cost": 4239.732514568286
      },
      "source": "hand calculation in content.mdx: Gmb = 2.45 × (1 − 0.04) = 2.352, so 2,352 kg/m³ (Asphalt Institute MS-2 air voids definition); 14.158 m³ × 2,352 × 1.05 = 34,965 kg = 38.54 tons; × $110 = $4,239.73; Asphalt Institute, MS-2 Asphalt Mix Design Methods, 7th edition: air voids and bulk specific gravity of compacted mix. https://bookstore.asphaltinstitute.org/catalog/book/ms-2-asphalt-mix-design-methods; NIST Handbook 44 (2026), Appendix C, General Tables of Units of Measurement: 1 cubic yard = 27 cubic feet, 1 short ton = 2,000 pounds. https://www.nist.gov/document/2026-nist-handbook-44-appendix-c"
    },
    {
      "given": {
        "geometryMethod": "direct",
        "area": 464.51520000000005,
        "thick": 0.0508,
        "wasteFactor": 0,
        "airVoids": 4,
        "density": 2322.67718922422,
        "price": 100,
        "delivery": 250
      },
      "expect": {
        "tons": 54809.07804166667,
        "cost": 6291.666666666666
      },
      "source": "hand calculation in content.mdx: 5,000 ft² × 2/12 ft × 145 lb/ft³ = 120,833 lb = 60.42 tons; × $100 + $250 = $6,291.67; NIST Handbook 44 (2026), Appendix C, General Tables of Units of Measurement: 1 cubic yard = 27 cubic feet, 1 short ton = 2,000 pounds. https://www.nist.gov/document/2026-nist-handbook-44-appendix-c"
    }
  ],
  "sources": [
    "NIST Handbook 44 (2026), Appendix C, General Tables of Units of Measurement: 1 cubic yard = 27 cubic feet; 1 short ton = 2,000 pounds. https://www.nist.gov/document/2026-nist-handbook-44-appendix-c",
    "Asphalt Institute, MS-2 Asphalt Mix Design Methods, 7th edition: air voids and bulk specific gravity of compacted mix. https://bookstore.asphaltinstitute.org/catalog/book/ms-2-asphalt-mix-design-methods"
  ],
  "related": [],
  "changelog": [
    {
      "date": "2026-09-29",
      "note": "Worked examples name a published reference for their rule."
    }
  ]
}