All Calculators
Free energy and climate tools — pick a calculator and get instant results. No signup, no fees.
Home Energy Cost Calculator
Estimate your total annual home energy cost based on location, home size, and usage habits.
Energy SavingsElectric Bill Calculator
Break down your monthly electric bill by energy charge, fixed charge, and taxes.
Energy SavingsLED vs Incandescent Savings Calculator
Quantify annual savings and CO₂ reduction from switching to LED bulbs.
Energy SavingsInsulation Savings Calculator
Estimate heating and cooling savings from upgrading home insulation, including IRA tax credit info.
Energy SavingsHeating vs Cooling Cost Calculator
Compare your seasonal heating and cooling costs to find where your energy dollars actually go.
Energy SavingsHeating Cost by Fuel Type Calculator
Compare annual home heating costs across natural gas, electric, heat pump, propane, and heating oil.
Energy SavingsAppliance Energy Cost Calculator
Calculate the running cost of any appliance per day, month, and year by wattage and usage hours.
Energy SavingsSpace Heater Cost Calculator
Calculate the exact cost to run a space heater per hour, day, and month by wattage and electricity rate.
Energy SavingsWashing Machine Energy Cost Calculator
Calculate washing machine running cost per load, month, and year — including electricity and water costs.
Energy SavingsDryer Energy Cost Calculator
Calculate the exact cost to run your dryer per load, per month, and per year by dryer type and electricity rate.
Energy SavingsRefrigerator Energy Cost Calculator
Estimate how much your refrigerator costs to run annually and compare to ENERGY STAR savings.
Solar & RenewablesSolar Panel Savings Calculator
Estimate annual electricity savings from a solar installation based on location, system size, and current bill.
Solar & RenewablesSolar Panel ROI Calculator
Calculate payback period and 25-year return on investment for a solar system after incentives.
Solar & RenewablesSolar CO2 Offset Calculator
Calculate how much CO₂ your solar panels offset per year — with tree-planting and car-miles equivalents.
Solar & RenewablesWind Turbine Calculator
Estimate electricity output and savings from a small home wind turbine based on wind speed and system size.
Solar & RenewablesBattery Storage Calculator
Find the right battery storage size for a home solar setup and model the financial impact.
Solar & RenewablesGreen Home Upgrade ROI Calculator
Compare payback period and long-term return across solar, insulation, heat pump, LED, and smart thermostat.
Carbon FootprintCarbon Footprint Calculator
Calculate your total annual personal carbon footprint across electricity, gas, driving, flights, and diet.
Carbon FootprintHome Carbon Footprint Calculator
Calculate carbon emissions specifically from your home's heating, cooling, and appliances.
Carbon FootprintCar vs EV Carbon Calculator
Compare lifetime carbon emissions of a gasoline car vs an electric vehicle, including manufacturing.
Carbon FootprintFlight Carbon Calculator
Calculate CO₂ emissions per flight route and estimate offset requirements.
Carbon FootprintDiet Carbon Calculator
Quantify how your diet choices contribute to your personal carbon footprint.
Carbon FootprintTree Planting Offset Calculator
Calculate how many trees are needed to offset a given amount of CO₂ emissions.
Water & EnvironmentWater Usage Calculator
Estimate household water consumption by activity and identify the biggest reduction opportunities.
Water & EnvironmentRainwater Harvesting Calculator
Calculate annual rainwater collection potential from your roof and estimate water bill savings.