{
  "version": "v1",
  "source": "https://craftquantities.com",
  "licence": "CC BY 4.0",
  "licenceUrl": "https://creativecommons.org/licenses/by/4.0/",
  "attribution": "Craft Quantities — craftquantities.com",
  "documentation": "https://craftquantities.com/api/",
  "versioning": "Fields are added, never removed or repurposed, within a version. A breaking change becomes /api/v2/ and v1 keeps being built.",
  "slug": "baseplate-pier-size-calculator",
  "category": "materials-quantities",
  "title": "Column Pier Size from Baseplate Edge Distance Calculator",
  "description": "Size a column pier from its baseplate and the concrete margin wanted outside the plate, and get the concrete for the piers, waste included.",
  "url": "https://craftquantities.com/calculators/materials-quantities/baseplate-pier-size-calculator/",
  "json": "https://craftquantities.com/api/v1/calculators/baseplate-pier-size-calculator.json",
  "inputCount": 6,
  "testCaseCount": 2,
  "sourceCount": 2,
  "lastVerified": "2026-09-20",
  "citation": {
    "author": "Craft Quantities",
    "title": "Column Pier Size from Baseplate Edge Distance Calculator",
    "version": "1.0.0",
    "sourcesChecked": "2026-09-20",
    "url": "https://craftquantities.com/calculators/materials-quantities/baseplate-pier-size-calculator/",
    "accessDate": null,
    "accessDateNote": "Add the date you retrieved this. It is deliberately absent: a static file cannot know when you read it, and the build date would be wrong.",
    "permanentVersionedUrl": null,
    "permanentVersionedUrlNote": "Not offered. This site keeps no archive of previous builds, so any such URL would resolve to the current page or to nothing. The version and sourcesChecked fields identify the calculation instead.",
    "formats": {
      "plain": "Craft Quantities. Column Pier Size from Baseplate Edge Distance Calculator. Version 1.0.0. Sources checked 2026-09-20. https://craftquantities.com/calculators/materials-quantities/baseplate-pier-size-calculator/",
      "apa": "Craft Quantities. (2026). Column Pier Size from Baseplate Edge Distance Calculator (Version 1.0.0) [Web calculator]. Retrieved from https://craftquantities.com/calculators/materials-quantities/baseplate-pier-size-calculator/",
      "harvard": "Craft Quantities (2026) Column Pier Size from Baseplate Edge Distance Calculator (Version 1.0.0). Available at: https://craftquantities.com/calculators/materials-quantities/baseplate-pier-size-calculator/",
      "bibtex": "@misc{craftquantities-calculators-materials-quantities-baseplate-pier-size-calculator,\n  author       = {{Craft Quantities}},\n  title        = {Column Pier Size from Baseplate Edge Distance Calculator},\n  version      = {1.0.0},\n  year         = {2026},\n  howpublished = {\\url{https://craftquantities.com/calculators/materials-quantities/baseplate-pier-size-calculator/}},\n}"
    }
  },
  "inputs": [
    {
      "id": "plateLength",
      "label": "Baseplate Length",
      "type": "number",
      "dimension": "length",
      "defaultValue": 0.4,
      "min": 0.05,
      "max": 2,
      "step": 0.005,
      "help": "The plate's long dimension, off the fabrication drawing."
    },
    {
      "id": "plateWidth",
      "label": "Baseplate Width",
      "type": "number",
      "dimension": "length",
      "defaultValue": 0.4,
      "min": 0.05,
      "max": 2,
      "step": 0.005,
      "help": "The plate's other plan dimension."
    },
    {
      "id": "edgeDistance",
      "label": "Concrete Margin Wanted Outside the Plate",
      "type": "number",
      "dimension": "length",
      "defaultValue": 0.1,
      "min": 0.025,
      "max": 0.6,
      "step": 0.005,
      "help": "How much concrete stands outside every edge of the plate."
    },
    {
      "id": "pierHeight",
      "label": "Pier Height",
      "type": "number",
      "dimension": "length",
      "defaultValue": 0.9,
      "min": 0.1,
      "max": 6,
      "step": 0.01,
      "help": "From the top of whatever it stands on, up to the underside of the plate."
    },
    {
      "id": "pierCount",
      "label": "Number of Piers",
      "type": "number",
      "defaultValue": 4,
      "min": 1,
      "max": 200,
      "step": 1,
      "help": "How many identical piers this pour covers."
    },
    {
      "id": "wasteAllowance",
      "label": "Waste Allowance (%)",
      "type": "number",
      "defaultValue": 8,
      "min": 0,
      "max": 30,
      "step": 1,
      "help": "The margin for form deflection, spillage and over-break at the base."
    }
  ],
  "sources": [
    {
      "label": "Pier plan size = plate dimension + 2 × the edge distance wanted on each side; concrete volume = pier length × pier width × pier height × the number of piers, plus a waste allowance"
    },
    {
      "label": "The margin of concrete outside a baseplate is set by the anchor's edge-distance requirement and by the bearing assumption the plate was designed on — both come from the design, not from this page"
    }
  ],
  "testCases": [
    {
      "name": "Four 400 mm square plates, 100 mm margin, 900 mm piers, 8% waste",
      "inputs": {
        "plateLength": 0.4,
        "plateWidth": 0.4,
        "edgeDistance": 0.1,
        "pierHeight": 0.9,
        "pierCount": 4,
        "wasteAllowance": 8
      },
      "expected": 1.39968,
      "toleranceDecimalPlaces": 3,
      "unit": "m³",
      "confidence": "medium",
      "steps": [
        {
          "label": "Pier length",
          "value": 600.0000000000001,
          "unit": "mm"
        },
        {
          "label": "Pier width",
          "value": 600.0000000000001,
          "unit": "mm"
        },
        {
          "label": "Plan area of one pier",
          "value": 0.3600000000000001,
          "unit": "m²"
        },
        {
          "label": "Volume per pier",
          "value": 0.3240000000000001,
          "unit": "m³"
        },
        {
          "label": "Base volume before waste",
          "value": 1.2960000000000005,
          "unit": "m³"
        }
      ],
      "includesAllowance": {
        "label": "Form loss and over-break allowance",
        "percent": 8
      },
      "basis": "cited",
      "sourceIndex": 0
    },
    {
      "name": "One rectangular plate, 75 mm margin, 1.2 m pier, no waste",
      "inputs": {
        "plateLength": 0.5,
        "plateWidth": 0.3,
        "edgeDistance": 0.075,
        "pierHeight": 1.2,
        "pierCount": 1,
        "wasteAllowance": 0
      },
      "expected": 0.351,
      "toleranceDecimalPlaces": 4,
      "unit": "m³",
      "confidence": "medium",
      "steps": [
        {
          "label": "Pier length",
          "value": 650,
          "unit": "mm"
        },
        {
          "label": "Pier width",
          "value": 449.99999999999994,
          "unit": "mm"
        },
        {
          "label": "Plan area of one pier",
          "value": 0.2925,
          "unit": "m²"
        },
        {
          "label": "Volume per pier",
          "value": 0.351,
          "unit": "m³"
        },
        {
          "label": "Base volume before waste",
          "value": 0.351,
          "unit": "m³"
        }
      ],
      "includesAllowance": {
        "label": "Form loss and over-break allowance",
        "percent": 0
      },
      "basis": "cited",
      "sourceIndex": 0
    }
  ]
}