Environment
Calculators.
Carbon footprint, solar ROI, water usage, and recycling — measure your impact, then reduce it. Carbon footprint, solar ROI, water usage, recycling impact, and the food-system math behind everyday decisions. Measure your impact, model the reduction, and decide where the next dollar of effort actually moves the needle.
- You want to measure your household carbon footprint before changing anything.
- You're sizing a solar install or EV decision and want the payback math.
- You're choosing between recycling, composting, or food-waste interventions and want the carbon-equivalent comparison.
Pick by what you're deciding
The same pages, grouped by the question you're trying to answer.
Carbon footprint & emissions
Household, flight, food-mile, and offset math — every major source quantified.
Solar, EV & home energy
Solar ROI, EV charging cost, battery storage, and the wind/audit math.
Water conservation
Household usage, conservation savings, rainwater capture.
Recycling & food waste
Plastic footprint, compost savings, food miles, and the circular-economy math.
Carbon & Emissions
7 toolsMeasure your carbon footprint from energy, transport, and diet — then find ways to offset it.
Carbon Footprint
Annual CO₂ from electricity, gas, car, flights, and diet.
Flight Carbon
CO₂ per flight with radiative forcing and class factors.
Carbon Offset
Trees and cost needed to offset your emissions.
Deforestation Impact
Carbon sequestration, oxygen, and ecosystem value by forest type.
Tree Planting
How many trees to plant to offset your carbon footprint, by species and climate zone.
AQI Health Impact
PM2.5 and AQI converted to cigarette equivalents and health risk by profile.
Eco Driving Fuel Savings
Quantify fuel and CO₂ savings from fixing speeding, hard braking, idling, and other bad habits.
Solar & Energy
3 toolsModel solar panel savings, battery storage ROI, and EV charging costs with real sun-hour data.
Solar ROI Detailed
20-year NPV, IRR, and payback with federal tax credit.
Wind Energy Calculator
Annual wind turbine output, savings, payback period, and 20-year ROI.
Home Energy Audit
Annual energy cost, EUI grade, and ranked upgrade ROI with payback periods.
EV Charging Cost
Daily, monthly & annual EV charging cost vs. gasoline.
Solar Panel Savings
Monthly bill to system size, annual savings, 25-yr ROI, and payback.
Solar Battery Storage
Grid independence, backup hours, and TOU savings for home batteries.
Renewable Energy Payback
Simple payback, discounted payback, IRR, NPV, and CO₂ avoided for 5 clean energy technologies.
Green Building Cost
LEED, Energy Star & Passive House premium cost, ROI, and CO₂ savings.
Water
3 toolsTrack household water use, find conservation savings, and explore rainwater harvesting potential.
Recycling
5 toolsSee exactly how much energy and CO₂ you save by recycling each material type — and how your diet and garden affect local biodiversity.
Recycling Savings
Energy and CO₂ saved per pound of recycled material.
Plastic Footprint
Annual plastic pieces, weight, and CO₂ from your single-use habits.
Compost Savings
Annual fertilizer savings, methane avoided, and net composting cost-benefit.
Biodiversity Impact
Land use footprint, species-equivalents, and planetary boundary from diet, flights, and garden habits.
Circular Economy Impact
CO₂, energy & water saved by recycling 6 material types annually.
Food & Waste
2 toolsThe average American wastes over 200 pounds of food per year. Quantify yours.
Frequently asked questions
Whose emission factors do these calculators use?
Per-source factors come from the EPA eGRID (US electricity), DEFRA / GHG Protocol (international transport), USDA (food), and IPCC AR6 (radiative forcing on flights). Each calculator names its source and the year of the factor.
Does the carbon-footprint calculator include scope 3?
The household calculator covers direct (scope 1: gas, oil) and indirect-energy (scope 2: electricity) plus the most material scope 3 categories (driving, flights, diet). Embedded emissions in goods consumed are estimated using national averages.
How accurate is solar ROI?
Within 10–15% for a typical residential install, given accurate inputs for system size, local kWh rate, net-metering policy, and federal/state incentives. Each input has tooltip-level guidance on how to find your real number. For a binding quote, get two installer bids — the calculator is for the decision framework, not the contract.
Why are some impact metrics in CO2-equivalent vs straight kg?
Greenhouse gases have different warming potencies (methane is ~28x CO2 over 100 years; refrigerants can be 1,000s of times higher). CO2-equivalent (CO2e) normalizes everything to a common scale so you can compare a flight to a steak. Each calculator labels its units explicitly.