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 SavingsAC Running Cost Calculator
Calculate how much your air conditioner costs to run per hour, day, and month — by BTU, SEER rating, and local electricity rate.
Energy SavingsDemand Response Savings Estimator
Estimate how much your utility could pay you for letting them cycle your AC or thermostat during peak summer demand.
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.
Energy SavingsDehumidifier Running Cost Calculator
Calculate the cost to run a dehumidifier per hour, day, month, and year by pint capacity and duty cycle.
Energy SavingsPool Pump Running Cost Calculator
Calculate pool pump running cost per day, month, and season — and see single-speed vs variable-speed savings.
Energy SavingsHumidifier Running Cost Calculator
Calculate humidifier running cost per hour, day, month, and year — and compare cool mist vs warm mist cost.
Energy SavingsChest & Upright Freezer Running Cost Calculator
Calculate chest or upright freezer running cost per month and year — and see how much a chest freezer saves.
Energy SavingsHot Tub Running Cost Calculator
Calculate hot tub running cost per day, month, and year — and compare inflatable vs built-in electricity costs.
Energy SavingsBudget Billing Estimator
See your estimated levelized monthly payment, seasonal cash-flow difference, and true-up risk range before enrolling in budget or levelized billing.
Energy SavingsEV Charging Cost Calculator
Monthly home charging cost, how much an off-peak rate would save you, what public fast charging adds, and the comparison against gasoline.
Energy SavingsWhy Is My Electric Bill So High?
Find out which appliances or habits are responsible for a bill spike, and exactly how much each one costs you.
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.
Solar & RenewablesNet Metering Calculator
See what your exported solar power is really worth under full retail net metering vs net billing (NEM 3.0), and why self-consumption matters more than the policy.
Solar & RenewablesCommunity Solar Savings Calculator
No roof required. See your real net savings after both bills — the utility bill and the subscription invoice — and how it compares to rooftop solar.
Solar & RenewablesHow Many Solar Panels Do I Need?
Enter your monthly electricity use, sun hours, and panel wattage to get exact panel count, system size, and estimated cost.
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.
Carbon FootprintAI Chatbot Carbon Footprint Calculator
Estimate the CO₂ from your daily ChatGPT, Gemini, or Claude use based on disclosed energy figures.
Water & EnvironmentWater Bill Benchmark Calculator
Enter the usage number off your bill in any unit — CCF, CF, gallons, m³ — and find out whether it's normal for your household size.
Water & EnvironmentWater Usage Calculator
Estimate household water consumption by activity and identify the biggest reduction opportunities.
Water & EnvironmentAI Water Footprint Calculator
Estimate the water behind your ChatGPT or Gemini use, and see why estimates range from 5 drops to a full bottle.
Water & EnvironmentRainwater Harvesting Calculator
Calculate annual rainwater collection potential from your roof and estimate water bill savings.
Water & EnvironmentWashing Machine Water Usage Calculator
Enter your washer type and weekly loads to get exact gallons per load, annual water use, and savings from upgrading to ENERGY STAR.