Energy & Environment calculators
Electricity cost, solar payback, carbon footprint and appliance energy.
38 free tools
Most used
Carbon Footprint CalculatorEstimate your household’s yearly CO₂ from energy, driving, flights and foodElectricity Cost CalculatorSee what any appliance costs to run per hour, day, month and yearPropane Tank Duration CalculatorFind out how many hours or days your propane tank will lastSolar Panel CalculatorFind how many solar panels and what system size you needSolar Panel Output CalculatorEstimate the kWh your solar panels produce per day, month and yearUK Energy Price Cap CalculatorEstimate your gas and electricity bill under the Ofgem price cap
More energy & environment tools
Air Purifier Size CalculatorFind the CADR your air purifier needs for any room sizeBattery Backup CalculatorSize a home battery or power station for the load and hours you needCar CO2 Emissions CalculatorSee how much CO2 your car emits per trip, per mile and per yearDehumidifier Size CalculatorFind the right dehumidifier pint capacity for your room or basementGas Meter Reading to kWh CalculatorTurn two gas meter readings into kWh and a cost, the way suppliers doGenerator Fuel Consumption CalculatorEstimate fuel burn, runtime per tank and cost for any generator loadHeating Cost CalculatorCompare yearly heating costs for gas, propane, oil, electric and heat pumpsHeating Fuel Cost ComparisonCompare the true cost per million BTU of seven heating fuelsInsulation Payback CalculatorSee how fast new attic or wall insulation pays for itselfLED Savings CalculatorSee how much you save by switching light bulbs to LEDPool Heater Size CalculatorFind the BTU rating your pool heater needs to heat up and hold temperatureSolar Charge Controller CalculatorSize an MPPT or PWM charge controller for your panels and battery bankSolar Payback CalculatorFind when solar panels pay for themselves and your lifetime returnWater Heater Cost CalculatorCompare yearly running costs of electric, gas, tankless and heat pump unitsAppliance 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 passengersFood Carbon Footprint CalculatorSee the greenhouse gas emissions of what you eat each week and yearHeat Pump vs Furnace CalculatorCompare yearly heating costs and payback of a heat pump against a gas furnaceHeating Degree Days CalculatorTurn daily temperatures into heating and cooling degree daysHome Battery Payback CalculatorFind out how long a home battery takes to pay for itselfInverter Size CalculatorFind the inverter wattage you need for running and surge loadsPhantom Load CalculatorFind what standby “vampire” power from plugged-in devices costs you each yearRainwater 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 monthTiered Electricity Rate CalculatorWork out your electric bill under tiered (block) rates, fees and taxesTime-of-Use Rate CalculatorSee whether a time-of-use electricity plan beats a flat rate for your usageTree Carbon Sequestration CalculatorEstimate how much CO₂ a tree has stored from its trunk diameter and speciesWater 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 speedWindow Replacement Savings CalculatorEstimate the energy savings and payback of new, lower U-factor windows