Home Energy Calculators
Use 80 transparent calculators for solar, batteries, electrical loads, EV charging, heating and cooling, and backup power. Every tool includes formulas, input guidance, limitations, FAQs, sources, and related calculations.
Solar Calculators
Plan residential solar capacity, production, panel count, PV strings, roof area, exports, payback, storage, and EV charging energy. Includes 21 interactive tools.
17 toolsBattery Calculators
Estimate battery runtime, charging time, current, usable energy, capacity conversions, expansion, degradation, and payback. Includes 17 interactive tools.
12 toolsElectrical Calculators
Calculate inverter capacity, electricity cost, AC and DC current, power factor, voltage drop, and single- or three-phase power. Includes 12 interactive tools.
10 toolsEV Charging Calculators
Estimate EV charging time, home and public charging cost, charger size, circuit demand, solar requirements, and tariff savings. Includes 10 interactive tools.
11 toolsHeating & Cooling Calculators
Estimate heat-pump and mini-split operating cost, COP, heating comparisons, water-heater savings, degree days, and cooling expense. Includes 11 interactive tools.
9 toolsBackup Power Calculators
Size generators, essential loads, portable power stations, UPS systems, whole-home batteries, and compare backup ownership costs. Includes 9 interactive tools.
How to use the calculator library
Start with the calculator closest to the decision you need to make. Save the input values and source documents, calculate expected and conservative cases, and use related tools to check power, energy, runtime, cost, and equipment limits separately. Word count does not create accuracy; reliable inputs, visible formulas, primary sources, and verification do.