{
  "id": "dirt",
  "version": "64293bd67dcf",
  "status": "published",
  "name": "Dirt Calculator",
  "question": "How much dirt do I need?",
  "summary": "Computes the fill dirt to fill a rectangular or round area to a depth, with extra for compaction, in cubic yards, cubic feet and cubic metres, its weight in tons, and the cost.",
  "category": "construction",
  "subcategory": "garden",
  "url": "https://www.acalculator.org/construction/dirt-calculator",
  "markdown": "https://www.acalculator.org/construction/dirt-calculator.md",
  "kind": "function",
  "method": "Volume = length × width × depth (or π × diameter² ÷ 4 × depth) × (1 + extra ÷ 100); cubic yards = cubic feet ÷ 27; tons = cubic yards × tons per cubic yard; tonnes = tons × 0.90718474.",
  "assumptions": [
    "Extra for compaction is 10% by default (NeedsDirt: 10% to 15% for non-structural grading, 15% to 30% for structural fill).",
    "One cubic yard of fill dirt weighs 1.2 US tons by default (NeedsDirt: 1.2 to 1.5 tons, by moisture and make-up). Type your supplier’s figure.",
    "The area is filled level to the depth you type, with straight sides."
  ],
  "inputs": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "properties": {
      "shape": {
        "title": "Area shape",
        "description": "Whether the area to fill is a rectangle or a circle.",
        "type": "string",
        "enum": [
          "rect",
          "circle"
        ]
      },
      "l": {
        "title": "Length",
        "description": "The length of the area to fill.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "length",
        "exclusiveMinimum": 0,
        "maximum": 10000
      },
      "w": {
        "title": "Width",
        "description": "The width of the area to fill.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "length",
        "exclusiveMinimum": 0,
        "maximum": 10000
      },
      "d": {
        "title": "Diameter",
        "description": "The diameter of a round hole or area.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "length",
        "exclusiveMinimum": 0,
        "maximum": 10000
      },
      "depth": {
        "title": "Depth",
        "description": "How deep to fill, after the dirt is packed down.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "length",
        "exclusiveMinimum": 0,
        "maximum": 1000
      },
      "extra": {
        "title": "Extra for compaction",
        "description": "Loose dirt to add, in percent, because it packs down: 10% to 15% for ordinary grading.",
        "type": "number",
        "x-unit": "percent",
        "minimum": 0,
        "maximum": 100
      },
      "wt": {
        "title": "Weight per cubic yard (tons)",
        "description": "How many US tons one cubic yard of your dirt weighs: about 1.2 to 1.5. Ask your supplier.",
        "type": "number",
        "minimum": 0,
        "maximum": 10
      },
      "price": {
        "title": "Price per cubic yard",
        "description": "What one cubic yard of dirt costs, delivered. Leave empty to skip the cost.",
        "type": "number",
        "x-unit": "USD",
        "minimum": 0,
        "maximum": 100000
      }
    }
  },
  "outputs": {
    "cubicYards": {
      "label": "Cubic yards",
      "description": "The dirt to order, in cubic yards (27 cubic feet each).",
      "format": "number"
    },
    "cubicFeet": {
      "label": "Cubic feet",
      "description": "The dirt to order, in cubic feet.",
      "format": "number"
    },
    "cubicMeters": {
      "label": "Cubic metres",
      "description": "The dirt to order, in cubic metres.",
      "format": "number"
    },
    "tons": {
      "label": "Weight (US tons)",
      "description": "Cubic yards × the weight per cubic yard, in tons of 2,000 lb.",
      "format": "number"
    },
    "tonnes": {
      "label": "Weight (tonnes)",
      "description": "The same weight in metric tonnes of 1,000 kg.",
      "format": "number"
    },
    "cost": {
      "label": "Cost",
      "description": "Cubic yards × the price per cubic yard.",
      "format": "money"
    }
  },
  "defaultAnswer": {
    "inputs": {
      "shape": "rect",
      "l": 6.096,
      "w": 3.048,
      "d": 3.048,
      "depth": 0.15239999999999998,
      "extra": 10,
      "wt": 1.2
    },
    "outputs": {
      "cubicYards": 4.074074074074074,
      "cubicFeet": 110,
      "cubicMeters": 3.11485312512,
      "tons": 4.888888888888889,
      "tonnes": 4.435125395555556
    },
    "text": "Order 4.07 yd³ of dirt (110 ft³), about 4.89 tons."
  },
  "examples": [
    {
      "given": {
        "shape": "rect",
        "l": 6.096,
        "w": 3.048,
        "depth": 0.15239999999999998,
        "extra": 10,
        "wt": 1.2
      },
      "expect": {
        "cubicFeet": 110,
        "cubicYards": 4.074074074074074,
        "tons": 4.888888888888889
      },
      "source": "NeedsDirt, How to Calculate Fill Dirt Needed (add 10 to 15% for non-structural grading; 1.2 to 1.5 tons per cubic yard), https://needsdirt.com/guides/how-to-calculate-fill-dirt-needed-contractor-s-complete-guide; hand calculation in content.mdx: 20 × 10 × 0.5 × 1.1 = 110 ft³ = 4.07 yd³ × 1.2 = 4.89 tons"
    },
    {
      "given": {
        "shape": "rect",
        "l": 8.2296,
        "w": 0.3048,
        "depth": 0.30479999999999996,
        "extra": 0,
        "wt": 1.5,
        "price": 30
      },
      "expect": {
        "cubicYards": 1,
        "tons": 1.5,
        "tonnes": 1.36077711,
        "cost": 30
      },
      "source": "NIST Handbook 44 (2026), Appendix C (1 yd³ = 27 ft³; 1 short ton = 2,000 lb = 0.90718474 t); hand calculation in content.mdx: 27 × 1 × 1 = 27 ft³ = 1 yd³; 1.5 tons = 1.36077711 t"
    },
    {
      "given": {
        "shape": "rect",
        "l": 5,
        "w": 4,
        "depth": 0.3,
        "extra": 15,
        "wt": 1.2
      },
      "expect": {
        "cubicMeters": 6.9,
        "cubicYards": 9.024859273269307
      },
      "source": "NIST Handbook 44 (2026), Appendix C (1 yd³ = 0.764554857984 m³); hand calculation in content.mdx: 5 × 4 × 0.3 × 1.15 = 6.9 m³ ÷ 0.764554857984 = 9.02 yd³"
    },
    {
      "given": {
        "shape": "circle",
        "d": 3.048,
        "depth": 0.6095999999999999,
        "extra": 0,
        "wt": 1.2
      },
      "expect": {
        "cubicFeet": 157.07963267948966,
        "cubicYards": 5.817764173314432
      },
      "source": "Cylinder volume π × d² ÷ 4 × depth (OpenStax, Prealgebra 2e, §9.6); hand calculation in content.mdx: π × 100 ÷ 4 × 2 = 157.08 ft³ = 5.82 yd³"
    }
  ],
  "sources": [
    "NeedsDirt, How to Calculate Fill Dirt Needed: A Contractor’s Complete Guide (add 10–15% for non-structural grading and 15–30% for structural fill; a cubic yard weighs 1.2 to 1.5 tons). https://needsdirt.com/guides/how-to-calculate-fill-dirt-needed-contractor-s-complete-guide (retrieved 2026-10-01)",
    "Engineering ToolBox, Dirt and Mud - Densities (dirt, loose dry 76 lb/ft³; clay, dry 100 lb/ft³). https://www.engineeringtoolbox.com/dirt-mud-densities-d_1727.html (retrieved 2026-10-01)",
    "NIST Handbook 44 (2026), Appendix C, General Tables of Units of Measurement: 1 yd³ = 27 ft³; 1 ft = 0.3048 m; 1 short ton = 2,000 lb; 1 lb = 0.45359237 kg. https://www.nist.gov/document/2026-nist-handbook-44-appendix-c (retrieved 2026-10-01)"
  ],
  "related": [
    "soil",
    "gravel",
    "cubic-yards",
    "mulch"
  ],
  "changelog": []
}