Home Energy Desk tools
Heating & Cooling Calculators
Estimate heat-pump and mini-split operating cost, COP, heating comparisons, water-heater savings, degree days, and cooling expense.
Explore every heating & cooling calculators
Heat Pump Running Cost Calculator
Estimate daily, monthly, and seasonal heat-pump electricity use, operating cost, and delivered heat.
Heat Pump vs Gas Heating Cost Calculator
Compare annual energy cost for a heat pump and a gas heating system while accounting for COP and combustion efficiency.
Heat Pump COP Calculator
Calculate coefficient of performance and electrical input from measured or rated heat output and power consumption.
Mini-Split Electricity Cost Calculator
Estimate mini-split monthly and annual electricity cost using rated input, runtime, duty cycle, and local electricity price.
Heat Pump Water Heater Savings Calculator
Compare annual electricity use and cost for a heat-pump water heater and a conventional electric resistance water heater.
Heating Degree Day Calculator
Calculate heating degree days for a period from base temperature, average outdoor temperature, and number of days.
Air Conditioner and Heat Pump Cooling Cost Calculator
Estimate cooling electricity use and cost from cooling capacity, SEER, operating hours, duty cycle, and electricity rate.
Heat Pump Size Calculator
Estimate a preliminary heat-pump heating and cooling capacity range using floor area, climate, insulation, air leakage, ceiling height, and design-temperature severity.
Heat Pump Balance Point Calculator
Estimate the outdoor temperature where a building heat loss equals the available heat-pump output and supplemental heat may begin.
SEER2, EER2 and HSPF2 Energy Cost Calculator
Estimate seasonal cooling and heating electricity use and cost from SEER2, EER2, HSPF2, capacity, operating hours, and electricity rate.
Water Heater Size and First-Hour Rating Calculator
Estimate storage water-heater tank size, peak-hour hot-water demand, and required first-hour rating for a household.
How to use these tools
Choose the calculator that matches your decision, enter values from equipment labels, utility bills, manuals, or verified specifications, and test more than one scenario. Calculator results are planning estimates. Confirm electrical, structural, HVAC, battery, and code-sensitive decisions with qualified professionals and applicable local requirements.