Energy & Environment calculators
Electricity cost, solar payback, carbon footprint and appliance energy.
18 free tools
Most used
More energy & environment tools
Battery Backup CalculatorSize a home battery or power station for the load and hours you needHeating Cost CalculatorCompare yearly heating costs for gas, propane, oil, electric and heat pumpsLED Savings CalculatorSee how much you save by switching light bulbs to LEDSolar Payback CalculatorFind when solar panels pay for themselves and your lifetime returnAppliance Replacement Payback CalculatorFind out how fast an efficient new appliance pays for itselfCarbon Offset CalculatorSee how many trees or carbon credits it takes to balance your CO₂Firewood CalculatorConvert a woodpile to cords and face cords and see its real heat valueFlight Carbon CalculatorEstimate the CO2 footprint of any flight by distance, cabin class and passengersHeat Pump vs Furnace CalculatorCompare yearly heating costs and payback of a heat pump against a gas furnaceInverter Size CalculatorFind the inverter wattage you need for running and surge loadsRainwater Harvesting CalculatorSee how much rain your roof can collect and what size tank you needSolar Panel Angle CalculatorFind the best tilt angle for solar panels at your latitude, by season and monthTime-of-Use Rate CalculatorSee whether a time-of-use electricity plan beats a flat rate for your usageWater Usage CalculatorEstimate how much water your household uses each day, month and yearWind Turbine CalculatorEstimate wind turbine power and yearly kWh from rotor size and wind speed