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Search or filter 108 tools—start with the most used, then open the full directory when you need more.
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PopularBattery Runtime
Estimate how long a battery lasts at a given power draw.
Ah to Wh Converter
Convert amp-hours to watt-hours using battery voltage.
EV Charging Cost
Estimate home charging cost from energy used and your utility rate.
Watts to Amps
Convert electrical power (watts) to current (amps) at a given voltage.
Battery Bank Size (Ah)
Size a battery bank in amp-hours from load, runtime, and voltage.
Battery Charging Time
Calculate how long it takes to charge a battery at a given current.
Solar Daily Yield
Estimate daily energy output from panel wattage and sun hours.
Solar Panel Size
Estimate minimum panel wattage from daily energy use and sun hours.
Residential AC Voltage Drop Calculator
Calculate AC voltage drop in home wiring from supply voltage, amps, cable length (m), and AWG or mm² copper size.
Solar Payback Period (ROI) Calculator
Estimate payback time and 25-year savings from system cost, production, and electricity rates.