{
  "slug": "carbon-footprint-home",
  "title": "Home Carbon Footprint Calculator",
  "heading": "Home Energy Carbon Footprint Calculator",
  "category": "other",
  "url": "https://www.revenuelab.fyi/toolbox/carbon-footprint-home",
  "summary": "Estimate annual household CO2 emissions from electricity, natural gas, and heating fuel use.",
  "description": "Home energy use typically makes up 15-25% of a US household's total carbon footprint, split between electricity (whose carbon intensity depends entirely on your local grid mix) and direct fuel combustion for heating and hot water, which emits a fixed amount of CO2 per unit regardless of where you live. This calculator combines your annual electricity usage times your grid's carbon intensity with your natural gas or heating oil usage times EPA emission factors, giving a household total in line with how EPA and utility carbon-tracking tools calculate it. Natural gas emits about 5.3 kg CO2 per therm and heating oil about 10.16 kg CO2 per gallon — both fixed regardless of furnace efficiency, so efficiency only changes how many units you burn, not the per-unit factor.",
  "formula": "CO2 = (kWh × grid intensity) + (therms × 5.3 kg/therm) + (heating oil gallons × 10.16 kg/gal).",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=carbon-footprint-home",
  "inputs": [
    {
      "id": "kwh",
      "label": "Annual electricity use",
      "kind": "number",
      "hint": null,
      "default": 10500,
      "unit": "kWh",
      "min": 0,
      "max": null
    },
    {
      "id": "gridIntensity",
      "label": "Grid carbon intensity",
      "kind": "number",
      "hint": null,
      "default": 0.37,
      "unit": "kg CO2/kWh",
      "min": 0,
      "max": 1
    },
    {
      "id": "therms",
      "label": "Annual natural gas use",
      "kind": "number",
      "hint": null,
      "default": 500,
      "unit": "therms",
      "min": 0,
      "max": null
    },
    {
      "id": "oilGallons",
      "label": "Annual heating oil use",
      "kind": "number",
      "hint": null,
      "default": 0,
      "unit": "gal",
      "min": 0,
      "max": null
    }
  ],
  "outputs": [
    {
      "id": "totalKg",
      "label": "Total annual home CO2 (kg)",
      "format": "number",
      "hint": null,
      "primary": true
    },
    {
      "id": "tonnes",
      "label": "Total (metric tonnes)",
      "format": "decimal",
      "hint": null,
      "primary": false
    },
    {
      "id": "elecKg",
      "label": "From electricity",
      "format": "number",
      "hint": null,
      "primary": false
    },
    {
      "id": "gasKg",
      "label": "From natural gas",
      "format": "number",
      "hint": null,
      "primary": false
    },
    {
      "id": "oilKg",
      "label": "From heating oil",
      "format": "number",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Annual electricity use: 10500 kWh",
      "Grid carbon intensity: 0.37 kg CO2/kWh",
      "Annual natural gas use: 500 therms",
      "Annual heating oil use: 0 gal"
    ],
    "outputs": [
      "Total annual home CO2 (kg): 6,535",
      "Total (metric tonnes): 6.54",
      "From electricity: 3,885",
      "From natural gas: 2,650",
      "From heating oil: 0"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter annual electricity use (kWh).",
      "Enter grid carbon intensity (kg CO2/kWh).",
      "Enter annual natural gas use (therms).",
      "Enter annual heating oil use (gal).",
      "Read your total annual home co2 (kg) 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": {
        "kwh": 6300,
        "gridIntensity": 0.222,
        "therms": 300,
        "oilGallons": 0
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "kwh": 10500,
        "gridIntensity": 0.37,
        "therms": 500,
        "oilGallons": 0
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "kwh": 16800,
        "gridIntensity": 0.592,
        "therms": 800,
        "oilGallons": 0
      }
    }
  ],
  "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": "Why does the same electricity usage produce different emissions in different homes?",
      "a": "Grid carbon intensity varies by region based on the generation mix — coal-heavy grids emit far more CO2 per kWh than grids dominated by hydro, nuclear, wind, or solar. The same 10,000 kWh of annual use can range from under 1,000 kg CO2 to over 7,000 kg depending purely on location."
    },
    {
      "q": "How can I lower my home's carbon footprint fastest?",
      "a": "Switching from resistance or oil heat to a heat pump usually delivers the largest single reduction since it moves heating from direct fuel combustion to electricity, which you can then decarbonize further with rooftop solar or a green power plan from your utility."
    },
    {
      "q": "Why don't furnace or water heater efficiency ratings appear in this formula?",
      "a": "Efficiency changes how much fuel you burn for a given heat output, which is already reflected in your actual therms or gallons used on your utility bill — the emission factor per unit of fuel burned stays fixed regardless of appliance efficiency."
    },
    {
      "q": "Is natural gas cleaner than heating oil for the same heat output?",
      "a": "Per unit of heat delivered, natural gas generally emits less CO2 than heating oil, and modern high-efficiency gas furnaces (95%+ AFUE) further reduce fuel burned per BTU delivered compared to older oil systems, though methane leakage upstream in the gas supply chain is a separate, harder-to-quantify factor."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/carbon-footprint-drive",
    "https://www.revenuelab.fyi/toolbox/carbon-footprint-flight",
    "https://www.revenuelab.fyi/toolbox/tree-carbon-offset"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Home Carbon Footprint Calculator (https://www.revenuelab.fyi/toolbox/carbon-footprint-home)"
}