{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "name": "Answer tables: quantities for common jobs",
  "description": "The lookup tables published under /answers/, each row produced by driving this site's own calculator. Quantities for real jobs rather than rates to apply.",
  "source": "https://quantitywise.com/answers/",
  "publisher": "QuantityWise",
  "licence": "Free to use with attribution to https://quantitywise.com",
  "units": "metric",
  "reviewed": "2026-10-17",
  "provenance": "Derived: every row is what the named calculator outputs for the inputs stated in the set's note. A test re-runs each grid and fails the build on any disagreement, so these figures cannot drift from the tools.",
  "records": [
    {
      "id": "plasterboard-screws",
      "page": "/answers/what-size-screws-for-plasterboard/",
      "title": "Plasterboard screw length and count by board thickness and frame",
      "note": "A 4 × 3 m room, walls only, 2.4 m high, 12.5 mm board on timber for the counts. Length is board thickness plus the British Gypsum minimum penetration, rounded up to a size that is sold.",
      "calculator": "/plasterboard-calculator/",
      "rows": [
        {
          "label": "9.5 mm on timber",
          "sheets": "12",
          "screwLength": "38 mm (9.5 mm board + 25 mm into timber)",
          "screws": "304 (22 per sheet)",
          "screwWeight": "0.4 kg",
          "area": "30.5 m²"
        },
        {
          "label": "12.5 mm on timber",
          "sheets": "12",
          "screwLength": "38 mm (12.5 mm board + 25 mm into timber)",
          "screws": "304 (22 per sheet)",
          "screwWeight": "0.4 kg",
          "area": "30.5 m²"
        },
        {
          "label": "15 mm on timber",
          "sheets": "12",
          "screwLength": "42 mm (15 mm board + 25 mm into timber)",
          "screws": "304 (22 per sheet)",
          "screwWeight": "0.4 kg",
          "area": "30.5 m²"
        },
        {
          "label": "9.5 mm on metal",
          "sheets": "12",
          "screwLength": "25 mm (9.5 mm board + 10 mm into metal)",
          "screws": "304 (22 per sheet)",
          "screwWeight": "0.3 kg",
          "area": "30.5 m²"
        },
        {
          "label": "12.5 mm on metal",
          "sheets": "12",
          "screwLength": "25 mm (12.5 mm board + 10 mm into metal)",
          "screws": "304 (22 per sheet)",
          "screwWeight": "0.3 kg",
          "area": "30.5 m²"
        },
        {
          "label": "15 mm on metal",
          "sheets": "12",
          "screwLength": "25 mm (15 mm board + 10 mm into metal)",
          "screws": "304 (22 per sheet)",
          "screwWeight": "0.3 kg",
          "area": "30.5 m²"
        }
      ]
    },
    {
      "id": "plasterboard-screw-spacing",
      "page": "/answers/what-size-screws-for-plasterboard/",
      "title": "Plasterboard screw count by stud spacing",
      "note": "Same room, 12.5 mm board on timber. 300 mm along board edges, 400 mm in the field, plus a 15% allowance.",
      "calculator": "/plasterboard-calculator/",
      "rows": [
        {
          "label": "Studs at 400 mm",
          "sheets": "12",
          "screws": "414 (30 per sheet)",
          "screwWeight": "0.5 kg",
          "screwLength": "38 mm (12.5 mm board + 25 mm into timber)"
        },
        {
          "label": "Studs at 600 mm",
          "sheets": "12",
          "screws": "304 (22 per sheet)",
          "screwWeight": "0.4 kg",
          "screwLength": "38 mm (12.5 mm board + 25 mm into timber)"
        }
      ]
    },
    {
      "id": "tile-adhesive",
      "page": "/answers/how-much-tile-adhesive-do-i-need/",
      "title": "Tile adhesive and grout by tile size, over 10 m²",
      "note": "Flat substrate, 3 mm joint, 10 mm nominal tile thickness, 20 kg bags. Notch chosen from the tile’s equivalent side. Quantities include a 10% allowance.",
      "calculator": "/tile-calculator/",
      "rows": [
        {
          "label": "50 × 50 mosaic",
          "notch": "(3 mm notch)",
          "adhesive": "18.7 kg",
          "adhesiveBags": "1 × 20 kg",
          "grout": "19.4 kg",
          "groutBags": "4 × 5.0 kg"
        },
        {
          "label": "100 × 100",
          "notch": "(6 mm notch)",
          "adhesive": "33.0 kg",
          "adhesiveBags": "2 × 20 kg",
          "grout": "10.1 kg",
          "groutBags": "3 × 5.0 kg"
        },
        {
          "label": "150 × 150",
          "notch": "(6 mm notch)",
          "adhesive": "33.0 kg",
          "adhesiveBags": "2 × 20 kg",
          "grout": "6.8 kg",
          "groutBags": "2 × 5.0 kg"
        },
        {
          "label": "200 × 200",
          "notch": "(8 mm notch)",
          "adhesive": "44.0 kg",
          "adhesiveBags": "3 × 20 kg",
          "grout": "5.2 kg",
          "groutBags": "2 × 5.0 kg"
        },
        {
          "label": "300 × 300",
          "notch": "(8 mm notch)",
          "adhesive": "44.0 kg",
          "adhesiveBags": "3 × 20 kg",
          "grout": "3.5 kg",
          "groutBags": "1 × 5.0 kg"
        },
        {
          "label": "250 × 400",
          "notch": "(10 mm notch)",
          "adhesive": "55.0 kg",
          "adhesiveBags": "3 × 20 kg",
          "grout": "3.4 kg",
          "groutBags": "1 × 5.0 kg"
        },
        {
          "label": "200 × 500",
          "notch": "(10 mm notch)",
          "adhesive": "55.0 kg",
          "adhesiveBags": "3 × 20 kg",
          "grout": "3.6 kg",
          "groutBags": "1 × 5.0 kg"
        },
        {
          "label": "300 × 600",
          "notch": "(10 mm notch)",
          "adhesive": "55.0 kg",
          "adhesiveBags": "3 × 20 kg",
          "grout": "2.6 kg",
          "groutBags": "1 × 5.0 kg"
        },
        {
          "label": "450 × 450",
          "notch": "(10 mm notch)",
          "adhesive": "55.0 kg",
          "adhesiveBags": "3 × 20 kg",
          "grout": "2.3 kg",
          "groutBags": "1 × 5.0 kg"
        },
        {
          "label": "600 × 600",
          "notch": "(12 mm notch)",
          "adhesive": "66.0 kg",
          "adhesiveBags": "4 × 20 kg",
          "grout": "1.7 kg",
          "groutBags": "1 × 5.0 kg"
        },
        {
          "label": "200 × 1200 plank",
          "notch": "(12 mm notch)",
          "adhesive": "66.0 kg",
          "adhesiveBags": "4 × 20 kg",
          "grout": "3.0 kg",
          "groutBags": "1 × 5.0 kg"
        },
        {
          "label": "600 × 1200",
          "notch": "(15 mm notch)",
          "adhesive": "82.5 kg",
          "adhesiveBags": "5 × 20 kg",
          "grout": "1.3 kg",
          "groutBags": "1 × 5.0 kg"
        }
      ]
    },
    {
      "id": "paint-by-surface",
      "page": "/answers/how-much-paint-per-square-metre/",
      "title": "Paint for 29 m² of wall, by surface, two coats, unprimed",
      "note": "A 4 × 3 m room 2.4 m high, one door and one window deducted. Primer deliberately off, so the first-coat absorption falls on the finish paint and is visible.",
      "calculator": "/paint-calculator/",
      "rows": [
        {
          "label": "Previously painted, smooth",
          "litres": "5.0 L",
          "tins": "1 × 5 L",
          "alt": "",
          "area": "29.0 m²",
          "firstCoat": "2.42 L",
          "laterCoats": "2.42 L (1)"
        },
        {
          "label": "New plaster or skim (sealed)",
          "litres": "7.0 L",
          "tins": "1 × 5 L + 2 × 1 L",
          "alt": "Or 1 × 10 L — 3 L more paint, 2 fewer tins. Larger tins usually cost less per litre, so this is often cheaper.",
          "area": "29.0 m²",
          "firstCoat": "3.87 L (absorbs ×0.75)",
          "laterCoats": "2.90 L (1)"
        },
        {
          "label": "New plasterboard",
          "litres": "7.0 L",
          "tins": "1 × 5 L + 2 × 1 L",
          "alt": "Or 1 × 10 L — 3 L more paint, 2 fewer tins. Larger tins usually cost less per litre, so this is often cheaper.",
          "area": "29.0 m²",
          "firstCoat": "3.87 L (absorbs ×0.75)",
          "laterCoats": "2.90 L (1)"
        },
        {
          "label": "Textured, artex, heavy roll",
          "litres": "8.0 L",
          "tins": "1 × 5 L + 3 × 1 L",
          "alt": "Or 1 × 10 L — 2 L more paint, 3 fewer tins. Larger tins usually cost less per litre, so this is often cheaper.",
          "area": "29.0 m²",
          "firstCoat": "4.27 L (absorbs ×0.85)",
          "laterCoats": "3.63 L (1)"
        },
        {
          "label": "Render, brick, rough masonry",
          "litres": "12.0 L",
          "tins": "1 × 10 L + 2 × 1 L",
          "alt": "Or 1 × 10 L + 1 × 2.5 L — 0.5 L more paint, 1 fewer tin. Larger tins usually cost less per litre, so this is often cheaper.",
          "area": "29.0 m²",
          "firstCoat": "6.91 L (absorbs ×0.70)",
          "laterCoats": "4.84 L (1)"
        },
        {
          "label": "Wood trim, doors, joinery",
          "litres": "5.0 L",
          "tins": "1 × 5 L",
          "alt": "",
          "area": "29.0 m²",
          "firstCoat": "2.44 L (absorbs ×0.85)",
          "laterCoats": "2.07 L (1)"
        },
        {
          "label": "Metal, radiators, railings",
          "litres": "4.5 L",
          "tins": "1 × 2.5 L + 2 × 1 L",
          "alt": "Or 1 × 5 L — 0.5 L more paint, 2 fewer tins. Larger tins usually cost less per litre, so this is often cheaper.",
          "area": "29.0 m²",
          "firstCoat": "2.07 L",
          "laterCoats": "2.07 L (1)"
        }
      ]
    },
    {
      "id": "paint-by-room",
      "page": "/answers/how-much-paint-per-square-metre/",
      "title": "Paint by room size, two coats on previously painted walls",
      "note": "Ceilings 2.4 m, one door and one window deducted throughout. Rows ending \"+ ceiling\" include the ceiling at the same coverage rate.",
      "calculator": "/paint-calculator/",
      "rows": [
        {
          "label": "2 × 2 m",
          "litres": "2.5 L",
          "tins": "1 × 2.5 L",
          "alt": "",
          "area": "14.6 m²",
          "walls": "14.6 m²"
        },
        {
          "label": "3 × 3 m",
          "litres": "4.5 L",
          "tins": "1 × 2.5 L + 2 × 1 L",
          "alt": "Or 1 × 5 L — 0.5 L more paint, 2 fewer tins. Larger tins usually cost less per litre, so this is often cheaper.",
          "area": "24.2 m²",
          "walls": "24.2 m²"
        },
        {
          "label": "3 × 4 m",
          "litres": "5.0 L",
          "tins": "1 × 5 L",
          "alt": "",
          "area": "29.0 m²",
          "walls": "29.0 m²"
        },
        {
          "label": "4 × 4 m",
          "litres": "6.0 L",
          "tins": "1 × 5 L + 1 × 1 L",
          "alt": "",
          "area": "33.8 m²",
          "walls": "33.8 m²"
        },
        {
          "label": "4 × 5 m",
          "litres": "6.5 L",
          "tins": "1 × 2.5 L + 4 × 1 L",
          "alt": "Or 1 × 10 L — 3.5 L more paint, 4 fewer tins. Larger tins usually cost less per litre, so this is often cheaper.",
          "area": "38.6 m²",
          "walls": "38.6 m²"
        },
        {
          "label": "5 × 5 m",
          "litres": "7.5 L",
          "tins": "1 × 5 L + 1 × 2.5 L",
          "alt": "",
          "area": "43.4 m²",
          "walls": "43.4 m²"
        },
        {
          "label": "5 × 6 m",
          "litres": "8.5 L",
          "tins": "1 × 5 L + 1 × 2.5 L + 1 × 1 L",
          "alt": "Or 1 × 10 L — 1.5 L more paint, 2 fewer tins. Larger tins usually cost less per litre, so this is often cheaper.",
          "area": "48.2 m²",
          "walls": "48.2 m²"
        },
        {
          "label": "2 × 2 m + ceiling",
          "litres": "3.5 L",
          "tins": "1 × 2.5 L + 1 × 1 L",
          "alt": "",
          "area": "18.6 m²",
          "walls": "14.6 m²"
        },
        {
          "label": "3 × 3 m + ceiling",
          "litres": "6.0 L",
          "tins": "1 × 5 L + 1 × 1 L",
          "alt": "",
          "area": "33.2 m²",
          "walls": "24.2 m²"
        },
        {
          "label": "3 × 4 m + ceiling",
          "litres": "7.0 L",
          "tins": "1 × 5 L + 2 × 1 L",
          "alt": "Or 1 × 10 L — 3 L more paint, 2 fewer tins. Larger tins usually cost less per litre, so this is often cheaper.",
          "area": "41.0 m²",
          "walls": "29.0 m²"
        },
        {
          "label": "4 × 4 m + ceiling",
          "litres": "8.5 L",
          "tins": "1 × 5 L + 1 × 2.5 L + 1 × 1 L",
          "alt": "Or 1 × 10 L — 1.5 L more paint, 2 fewer tins. Larger tins usually cost less per litre, so this is often cheaper.",
          "area": "49.8 m²",
          "walls": "33.8 m²"
        },
        {
          "label": "4 × 5 m + ceiling",
          "litres": "10.0 L",
          "tins": "1 × 10 L",
          "alt": "",
          "area": "58.6 m²",
          "walls": "38.6 m²"
        },
        {
          "label": "5 × 5 m + ceiling",
          "litres": "11.5 L",
          "tins": "1 × 5 L + 1 × 2.5 L + 4 × 1 L",
          "alt": "Or 1 × 10 L + 1 × 2.5 L — 1 L more paint, 4 fewer tins. Larger tins usually cost less per litre, so this is often cheaper.",
          "area": "68.4 m²",
          "walls": "43.4 m²"
        },
        {
          "label": "5 × 6 m + ceiling",
          "litres": "13.5 L",
          "tins": "1 × 10 L + 1 × 2.5 L + 1 × 1 L",
          "alt": "",
          "area": "78.2 m²",
          "walls": "48.2 m²"
        }
      ]
    },
    {
      "id": "concrete-per-cubic-metre",
      "page": "/answers/how-many-bags-of-concrete/",
      "title": "Bags to one cubic metre of mixed concrete, by bag size",
      "note": "A 10 × 10 m slab 10 mm thick is exactly one cubic metre, with no waste added, so the bag count is the per-cubic-metre figure directly out of the tool.",
      "calculator": "/concrete-calculator/",
      "rows": [
        {
          "label": "20 kg",
          "volume": "1.00 m³",
          "bags": "108 × 20 kg bag",
          "weight": "2,160 kg"
        },
        {
          "label": "25 kg",
          "volume": "1.00 m³",
          "bags": "87 × 25 kg bag",
          "weight": "2,175 kg"
        },
        {
          "label": "30 kg",
          "volume": "1.00 m³",
          "bags": "72 × 30 kg bag",
          "weight": "2,160 kg"
        },
        {
          "label": "40 kg",
          "volume": "1.00 m³",
          "bags": "54 × 40 kg bag",
          "weight": "2,160 kg"
        },
        {
          "label": "40 lb",
          "volume": "1.00 m³",
          "bags": "118 × 40 lb bag",
          "weight": "2,141 kg"
        },
        {
          "label": "60 lb",
          "volume": "1.00 m³",
          "bags": "79 × 60 lb bag",
          "weight": "2,150 kg"
        },
        {
          "label": "80 lb",
          "volume": "1.00 m³",
          "bags": "59 × 80 lb bag",
          "weight": "2,141 kg"
        }
      ]
    },
    {
      "id": "concrete-slabs-20kg",
      "page": "/answers/how-many-bags-of-concrete/",
      "title": "Concrete for common slabs, 20 kg bags",
      "note": "5% added for spillage and over-dig.",
      "calculator": "/concrete-calculator/",
      "rows": [
        {
          "label": "Shed base 2 × 1.5 m, 100 mm",
          "volume": "0.32 m³",
          "bags": "34 × 20 kg bag",
          "weight": "680 kg",
          "readyMix": "0.5 m³"
        },
        {
          "label": "Path 5 × 1 m, 100 mm",
          "volume": "0.53 m³",
          "bags": "57 × 20 kg bag",
          "weight": "1,140 kg",
          "readyMix": "1.0 m³"
        },
        {
          "label": "Shed base 3 × 2 m, 100 mm",
          "volume": "0.63 m³",
          "bags": "68 × 20 kg bag",
          "weight": "1,360 kg",
          "readyMix": "1.0 m³"
        },
        {
          "label": "Shed base 3 × 3 m, 100 mm",
          "volume": "0.95 m³",
          "bags": "102 × 20 kg bag",
          "weight": "2,040 kg",
          "readyMix": "1.0 m³"
        },
        {
          "label": "Patio 4 × 3 m, 100 mm",
          "volume": "1.26 m³",
          "bags": "136 × 20 kg bag",
          "weight": "2,720 kg",
          "readyMix": "1.5 m³"
        },
        {
          "label": "Driveway 6 × 3 m, 150 mm",
          "volume": "2.84 m³",
          "bags": "305 × 20 kg bag",
          "weight": "6,100 kg",
          "readyMix": "3.0 m³"
        },
        {
          "label": "Garage base 6 × 6 m, 150 mm",
          "volume": "5.67 m³",
          "bags": "610 × 20 kg bag",
          "weight": "12,200 kg",
          "readyMix": "6.0 m³"
        }
      ]
    },
    {
      "id": "concrete-slabs-25kg",
      "page": "/answers/how-many-bags-of-concrete/",
      "title": "Concrete for common slabs, 25 kg bags",
      "note": "The same slabs, 5% added, in the other bag size people find on the shelf.",
      "calculator": "/concrete-calculator/",
      "rows": [
        {
          "label": "Shed base 2 × 1.5 m, 100 mm",
          "volume": "0.32 m³",
          "bags": "28 × 25 kg bag",
          "weight": "700 kg"
        },
        {
          "label": "Path 5 × 1 m, 100 mm",
          "volume": "0.53 m³",
          "bags": "46 × 25 kg bag",
          "weight": "1,150 kg"
        },
        {
          "label": "Shed base 3 × 2 m, 100 mm",
          "volume": "0.63 m³",
          "bags": "55 × 25 kg bag",
          "weight": "1,375 kg"
        },
        {
          "label": "Shed base 3 × 3 m, 100 mm",
          "volume": "0.95 m³",
          "bags": "82 × 25 kg bag",
          "weight": "2,050 kg"
        },
        {
          "label": "Patio 4 × 3 m, 100 mm",
          "volume": "1.26 m³",
          "bags": "109 × 25 kg bag",
          "weight": "2,725 kg"
        },
        {
          "label": "Driveway 6 × 3 m, 150 mm",
          "volume": "2.84 m³",
          "bags": "245 × 25 kg bag",
          "weight": "6,125 kg"
        },
        {
          "label": "Garage base 6 × 6 m, 150 mm",
          "volume": "5.67 m³",
          "bags": "489 × 25 kg bag",
          "weight": "12,225 kg"
        }
      ]
    },
    {
      "id": "concrete-post-holes",
      "page": "/answers/how-many-bags-of-concrete/",
      "title": "Concrete per fence post hole, 20 kg bags",
      "note": "One hole, 5% added, less the volume the post itself occupies.",
      "calculator": "/concrete-calculator/",
      "rows": [
        {
          "label": "75 mm post, 200 mm hole, 0.45 m",
          "volume": "0.01 m³",
          "bags": "2 × 20 kg bag",
          "weight": "40 kg"
        },
        {
          "label": "75 mm post, 250 mm hole, 0.60 m",
          "volume": "0.03 m³",
          "bags": "3 × 20 kg bag",
          "weight": "60 kg"
        },
        {
          "label": "100 mm post, 300 mm hole, 0.60 m",
          "volume": "0.04 m³",
          "bags": "5 × 20 kg bag",
          "weight": "100 kg"
        },
        {
          "label": "100 mm post, 300 mm hole, 0.75 m",
          "volume": "0.05 m³",
          "bags": "6 × 20 kg bag",
          "weight": "120 kg"
        },
        {
          "label": "100 mm post, 350 mm hole, 0.90 m",
          "volume": "0.08 m³",
          "bags": "9 × 20 kg bag",
          "weight": "180 kg"
        },
        {
          "label": "125 mm post, 400 mm hole, 1.00 m",
          "volume": "0.12 m³",
          "bags": "13 × 20 kg bag",
          "weight": "260 kg"
        }
      ]
    }
  ],
  "harvested": "2026-10-17"
}