{
  "slug": "12x12-concrete-slab-calculator",
  "title": "12x12 Concrete Slab Calculator",
  "heading": "12x12 Concrete Slab Calculator",
  "category": "other",
  "url": "https://www.revenuelab.fyi/toolbox/12x12-concrete-slab-calculator",
  "summary": "Yardage, bag count, and cost for a 12x12 patio or pad, defaulted and adjustable.",
  "description": "12x12 is a common footprint for a backyard patio slab or a standalone shed pad — big enough to be useful, small enough to pour in a weekend. This tool defaults to 12 feet by 12 feet at 4 inches thick, then converts that volume into ready-mix cubic yards, an equivalent 80-lb bag count for a hand-mixed pour, and a total dollar estimate so you can compare a delivery quote against DIY bags before committing.",
  "formula": "Cubic Yards = (Length × Width × Thickness in inches ÷ 12) ÷ 27 × (1 + Waste%). Bags (80lb) ≈ Cubic Yards × 45. Cost = Cubic Yards × Price per Yard.",
  "dateModified": "2026-09-06",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=12x12-concrete-slab-calculator",
  "inputs": [
    {
      "id": "length",
      "label": "Slab length",
      "kind": "number",
      "hint": null,
      "default": 12,
      "unit": "ft",
      "min": 1,
      "max": null
    },
    {
      "id": "width",
      "label": "Slab width",
      "kind": "number",
      "hint": null,
      "default": 12,
      "unit": "ft",
      "min": 1,
      "max": null
    },
    {
      "id": "thickness",
      "label": "Thickness",
      "kind": "number",
      "hint": null,
      "default": 4,
      "unit": "in",
      "min": 2,
      "max": 12
    },
    {
      "id": "waste",
      "label": "Waste factor",
      "kind": "number",
      "hint": null,
      "default": 10,
      "unit": "%",
      "min": 0,
      "max": 30
    },
    {
      "id": "pricePerYard",
      "label": "Ready-mix price per cubic yard",
      "kind": "number",
      "hint": null,
      "default": 150,
      "unit": "$",
      "min": 0,
      "max": null
    }
  ],
  "outputs": [
    {
      "id": "cubicYards",
      "label": "Ready-mix needed",
      "format": "decimal",
      "hint": null,
      "primary": true
    },
    {
      "id": "bags",
      "label": "80-lb bags (DIY mix)",
      "format": "number",
      "hint": null,
      "primary": false
    },
    {
      "id": "cost",
      "label": "Estimated concrete cost",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "cubicFeet",
      "label": "Total cubic feet",
      "format": "decimal",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Slab length: 12 ft",
      "Slab width: 12 ft",
      "Thickness: 4 in",
      "Waste factor: 10 %",
      "Ready-mix price per cubic yard: 150 $"
    ],
    "outputs": [
      "Ready-mix needed: 1.96",
      "80-lb bags (DIY mix): 88",
      "Estimated concrete cost: $293",
      "Total cubic feet: 48"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter slab length (ft).",
      "Enter slab width (ft).",
      "Enter thickness (in).",
      "Enter waste factor (%).",
      "Enter ready-mix price per cubic yard ($).",
      "Read your ready-mix needed 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": 7,
        "width": 7,
        "thickness": 2.4,
        "waste": 6,
        "pricePerYard": 90
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "length": 12,
        "width": 12,
        "thickness": 4,
        "waste": 10,
        "pricePerYard": 150
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "length": 19,
        "width": 19,
        "thickness": 6.4,
        "waste": 16,
        "pricePerYard": 240
      }
    }
  ],
  "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": "How many cubic yards for a 12x12 slab at 4 inches?",
      "a": "About 1.95 cubic yards with a 10% waste factor included — most concrete plants round that to a 2-yard minimum load."
    },
    {
      "q": "Do I need rebar or mesh in a 12x12 slab?",
      "a": "Wire mesh or rebar on a grid is standard for crack control on any slab over 100 square feet, and 12x12 (144 sq ft) qualifies."
    },
    {
      "q": "What's the difference between a 12x12 slab and patio pavers?",
      "a": "A poured slab is one continuous surface that resists weed growth and shifting, while pavers are individually replaceable but require a compacted base and edging. Slabs are usually cheaper per square foot for a simple rectangle."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/10x10-concrete-slab-calculator",
    "https://www.revenuelab.fyi/toolbox/20x20-concrete-slab-calculator"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — 12x12 Concrete Slab Calculator (https://www.revenuelab.fyi/toolbox/12x12-concrete-slab-calculator)"
}