{
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  "name": "How do you calculate concrete for footings?",
  "description": "Footing volume = length × width × depth ÷ 27. A continuous footing 60 ft long, 16 inches wide, 8 inches deep: 60 × 1.333 × 0.667 ÷ 27 = 1.98 yards. For post footings, use the cylinder formula: π × r² × depth ÷ 27 — a 12-inch diameter, 36-inch deep pier takes 0.087 yards, about 4 bags of 80-lb mix.",
  "url": "https://www.revenuelab.fyi/answers/how-to-calculate-concrete-for-footings",
  "dateModified": "2026-10-01",
  "creator": {
    "@type": "Organization",
    "name": "RevenueLab",
    "url": "https://www.revenuelab.fyi"
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  "license": "https://creativecommons.org/licenses/by/4.0/",
  "keywords": [
    "Concrete Cost Calculator",
    "Concrete Slab Cost Calculator",
    "Concrete Slab Material Calculator"
  ],
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    "@type": "DataDownload",
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  "json": {
    "type": "answer",
    "question": "How do you calculate concrete for footings?",
    "shortAnswer": "Footing volume = length × width × depth ÷ 27. A continuous footing 60 ft long, 16 inches wide, 8 inches deep: 60 × 1.333 × 0.667 ÷ 27 = 1.98 yards. For post footings, use the cylinder formula: π × r² × depth ÷ 27 — a 12-inch diameter, 36-inch deep pier takes 0.087 yards, about 4 bags of 80-lb mix.",
    "tableTitle": "Common footing sizes and volumes",
    "columns": [
      "Footing",
      "Dimensions",
      "Concrete needed"
    ],
    "rows": [
      {
        "label": "Deck pier",
        "value": "12 in dia × 36 in",
        "note": "0.087 yd³ ≈ 4 bags (80 lb)"
      },
      {
        "label": "Fence post",
        "value": "8 in dia × 24 in",
        "note": "0.026 yd³ ≈ 2 bags (80 lb)"
      },
      {
        "label": "Continuous wall footing",
        "value": "16 in wide × 8 in deep",
        "note": "0.033 yd³ per linear foot"
      },
      {
        "label": "Garage frost footing",
        "value": "24 in wide × 12 in deep",
        "note": "0.074 yd³ per linear foot"
      }
    ],
    "context": "Footing dimensions aren't a guess: width and depth come from the load and your frost depth, which building codes set by county — 12 inches in the deep South, 48+ inches in Minnesota. Pouring above the frost line is the classic cause of heaved decks and cracked foundations. Call 811 before digging, and order footings and slab separately if the pour schedule differs — footings often need to cure before forming continues.",
    "methodology": "Rectangular volume for continuous footings; cylinder volume (πr²d) for piers. Frost-depth and sizing requirements reference the International Residential Code (IRC R403) as adopted with local amendments — verify with your building department.",
    "dateModified": "2026-10-01",
    "relatedCalculators": [
      {
        "label": "Concrete Cost Calculator",
        "to": "/concrete-cost-calculator"
      },
      {
        "label": "Concrete Slab Cost Calculator",
        "to": "/concrete-slab-cost-calculator"
      },
      {
        "label": "Concrete Slab Material Calculator",
        "to": "/concrete-slab-material-calculator"
      }
    ],
    "relatedReading": [
      {
        "label": "Bags per cubic yard",
        "to": "/answers/how-many-bags-of-concrete-per-yard"
      }
    ]
  }
}