{
  "schemaVersion": 1,
  "slug": "ice-melt-calculator",
  "category": "household",
  "kind": "implementation",
  "independentValidation": false,
  "implementationHash": "1214352bcd7272837325070dd9ed113a50926b728c665e4447881940180c40c4",
  "provenance": "Generated from the calculation contract used by the published page. Publication is not external validation.",
  "sourceFiles": [
    "data/calculators/ice-melt-calculator.json",
    "src/engine.js"
  ],
  "runtimeSource": "/sources/engine.txt",
  "runtimeHash": "5c888d8898afbdee36267bb9977829e1e2ac568f6677c8ee87469c139864645c",
  "scope": "The compute function records implemented equations, constants, lookup tables and custom rules. Inputs record defaults and allowed values; outputs record precision and units. Defaults are examples, not recommendations. General background references are not evidence for this specific algorithm.",
  "publishedFormula": {
    "formula": "required = area × label rate ÷ 1,000; bags = ceil(required ÷ bag size)",
    "vars": [
      [
        "L",
        "Area length (ft)"
      ],
      [
        "W",
        "Area width (ft)"
      ],
      [
        "R",
        "Product label rate per 1,000 sq ft (lb / 1,000 ft²)"
      ],
      [
        "B",
        "Bag size (lb)"
      ]
    ],
    "note": "Use the application rate on the exact product label: product needed = area × label rate ÷ 1,000; whole bags = round up product needed ÷ bag size. Do not rely on a generic temperature or material rate."
  },
  "externalEvidence": {
    "reviewedAt": "2026-10-12",
    "sources": [
      {
        "name": "University of Minnesota Extension — product-label deicer guidance",
        "url": "https://extension.umn.edu/garden-and-home/yard-and-garden/lawns-and-landscapes-in-minnesota/the-effects-of-deicing-salts-on-landscapes"
      }
    ],
    "basis": "Multiply length by width, then multiply that area by the application rate printed on your exact product label per 1,000 ft². Divide the required weight by bag weight and round up for whole bags. Temperature and ice thickness are not inputs; the tool does not decide whether a product is suitable. Follow its label for temperature, surface and application limits.",
    "limitations": "Follow its label for temperature, surface and application limits.",
    "implementationHash": "1214352bcd7272837325070dd9ed113a50926b728c665e4447881940180c40c4",
    "domain": "home"
  },
  "contract": {
    "compute": "const area=length*width; const poundsNeeded=area*labelRate/1000; const bagsNeeded=Math.ceil(poundsNeeded/bagSize); return {area,poundsNeeded,bagsNeeded,warning:'Use the exact application rate and temperature range on your product label. This estimate does not account for surface, weather, or local restrictions; avoid over-application.'};",
    "inputs": [
      {
        "name": "length",
        "type": "number",
        "default": 40,
        "min": 1,
        "max": 1000,
        "step": 1
      },
      {
        "name": "width",
        "type": "number",
        "default": 12,
        "min": 1,
        "max": 200,
        "step": 1
      },
      {
        "name": "labelRate",
        "type": "number",
        "default": 3,
        "min": 0.1,
        "max": 100,
        "step": 0.1
      },
      {
        "name": "bagSize",
        "type": "number",
        "default": 20,
        "min": 1,
        "max": 200,
        "step": 1
      }
    ],
    "outputs": [
      {
        "name": "area",
        "precision": 1,
        "unit": "sq ft"
      },
      {
        "name": "poundsNeeded",
        "precision": 1,
        "unit": "lb"
      },
      {
        "name": "bagsNeeded",
        "precision": 1
      },
      {
        "name": "warning",
        "type": "text"
      }
    ],
    "interpret": null
  }
}