{
  "slug": "concrete-cubic-yards-calculator",
  "title": "Concrete Cubic Yards Calculator",
  "heading": "Concrete Cubic Yards Calculator",
  "category": "other",
  "url": "https://www.revenuelab.fyi/toolbox/concrete-cubic-yards-calculator",
  "summary": "Convert a slab, footing, or pad's dimensions straight into cubic yards of ready-mix.",
  "description": "Ready-mix concrete is sold and delivered by the cubic yard, so before you call a batch plant or a pump truck you need your pour's volume converted out of feet and inches. This calculator takes length, width, and thickness in feet (thickness entered in inches is converted automatically) and multiplies them to get cubic feet, then divides by 27 because one cubic yard equals 27 cubic feet. It also applies a waste factor, typically 5-10%, to cover subgrade irregularities, form leakage, and the reality that a slab is rarely a perfectly flat rectangle at exactly the thickness on the plan. Most ready-mix suppliers have a minimum load, often 1 cubic yard or a short-load fee below 3-4 yards, so knowing your real number before you call avoids both under-ordering (a cold joint mid-pour is a real defect) and over-ordering, which wastes money on a product you can't return. This is the same math used behind footings, patios, sidewalks, and driveway pours, just with different waste factors depending on how forgiving the subgrade prep was.",
  "formula": "Cubic Yards = (Length ft × Width ft × Thickness ft) ÷ 27, then × (1 + Waste%). Thickness ft = Thickness in ÷ 12.",
  "dateModified": "2026-09-06",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=concrete-cubic-yards-calculator",
  "inputs": [
    {
      "id": "length",
      "label": "Length",
      "kind": "number",
      "hint": null,
      "default": 20,
      "unit": "ft",
      "min": 0.5,
      "max": null
    },
    {
      "id": "width",
      "label": "Width",
      "kind": "number",
      "hint": null,
      "default": 10,
      "unit": "ft",
      "min": 0.5,
      "max": null
    },
    {
      "id": "thicknessIn",
      "label": "Thickness",
      "kind": "number",
      "hint": null,
      "default": 4,
      "unit": "in",
      "min": 1,
      "max": 24
    },
    {
      "id": "wastePct",
      "label": "Waste factor",
      "kind": "number",
      "hint": null,
      "default": 10,
      "unit": "%",
      "min": 0,
      "max": 30
    }
  ],
  "outputs": [
    {
      "id": "cubicYards",
      "label": "Concrete needed (with waste)",
      "format": "decimal",
      "hint": null,
      "primary": true
    },
    {
      "id": "cubicFeet",
      "label": "Total cubic feet",
      "format": "decimal",
      "hint": null,
      "primary": false
    },
    {
      "id": "cubicYardsRaw",
      "label": "Raw volume (no waste)",
      "format": "decimal",
      "hint": null,
      "primary": false
    },
    {
      "id": "bagsEquivalent80",
      "label": "Equivalent in 80lb bags",
      "format": "number",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Length: 20 ft",
      "Width: 10 ft",
      "Thickness: 4 in",
      "Waste factor: 10 %"
    ],
    "outputs": [
      "Concrete needed (with waste): 2.72",
      "Total cubic feet: 66.7",
      "Raw volume (no waste): 2.47",
      "Equivalent in 80lb bags: 122"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter length (ft).",
      "Enter width (ft).",
      "Enter thickness (in).",
      "Enter waste factor (%).",
      "Read your concrete needed (with waste) on the right — it updates as you type.",
      "Hit Share to keep the scenario or send it to someone."
    ]
  },
  "scenarios": [
    {
      "name": "Conservative",
      "description": "Lower-end numbers — what if things land soft?",
      "values": {
        "length": 12,
        "width": 6,
        "thicknessIn": 2.4,
        "wastePct": 6
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "length": 20,
        "width": 10,
        "thicknessIn": 4,
        "wastePct": 10
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "length": 32,
        "width": 16,
        "thicknessIn": 6.4,
        "wastePct": 16
      }
    }
  ],
  "limitations": [
    "Estimates assume standard, average conditions — local rules, pricing, and materials vary.",
    "Results are rounded for readability; add a buffer before ordering, booking, or committing.",
    "Double-check anything with a real cost attached against a local quote."
  ],
  "faq": [
    {
      "q": "Why divide by 27?",
      "a": "One cubic yard is 3 feet × 3 feet × 3 feet, which equals 27 cubic feet. Ready-mix trucks and batch plants price and measure in cubic yards, so every slab or footing calculation eventually needs that conversion."
    },
    {
      "q": "How much waste factor should I use?",
      "a": "5% for a well-formed, flat, prepped slab; 10% is the safe default for most DIY pours; 15%+ for irregular ground, thick footings, or if you're new to finishing concrete and expect some spillage or overpour at the edges."
    },
    {
      "q": "What if my slab thickness varies across the pour?",
      "a": "Use the thickest section for safety, or better, average several measurement points across the form since ready-mix trucks won't make a second trip for a shortfall without a hefty short-load fee."
    },
    {
      "q": "Is it cheaper to order ready-mix or mix bags for this volume?",
      "a": "Above roughly 1-1.5 cubic yards, ready-mix delivered is almost always cheaper per yard and far less labor than mixing 45-70 bags by hand or with a rented mixer."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/concrete-bags-80lb-calculator",
    "https://www.revenuelab.fyi/toolbox/concrete-slab-10x10-calculator",
    "https://www.revenuelab.fyi/toolbox/concrete-slab-12x12-calculator"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Concrete Cubic Yards Calculator (https://www.revenuelab.fyi/toolbox/concrete-cubic-yards-calculator)"
}