Power & electrical calculators
Precise, free tools for wire sizing, voltage drop, batteries, solar, and backup power.
Electrical
Look up AWG conductor diameter and cross-sectional area, 4/0 to 30 AWG.
Inverter Size Calculator
Size an inverter from your continuous load and largest single starting surge.
Battery Runtime Calculator
Estimate how long a battery will run a given load, from capacity, voltage, and depth of discharge.
Solar System Size Calculator
Estimate the solar array size and panel count needed to offset your daily energy use, from your own peak sun hours and system losses.
Generator Size Calculator
Calculate what size generator you need from your appliance list — running load, worst-case starting surge, and a suggested size.
kVA to kW Calculator
Convert between apparent power (kVA) and real power (kW) using your equipment's actual power factor.
Every calculator, grouped by the kind of problem it solves.
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