Physics

Estimate UPS battery backup runtime in minutes and hours using battery energy, device load, efficiency, battery health, and max output.

Calculate the continuous and surge watt ratings needed for appliances that may run at the same time.

List appliances and tools to estimate the running and starting watt ratings a generator should meet.

Estimate appliance electricity use and cost from watts, hours, days, rate, count, cycling use, and months per year.

Estimate a device’s electricity cost from power and runtime, or price known kWh from a bill, meter, or smart plug.

Estimate electricity cost from kWh using your rate, a U.S. planning rate, or a rate calculated from an electric bill.

Calculate appliance running watts from label watts or volts and amps, then estimate daily energy use and electricity cost.

Estimate home electrical load in VA and amps, compare standard and optional methods, and find the next service size from your list.

Calculate three-phase kW, amps, volts, power factor, kVA, kVAR, phase angle, and optional wye or delta phase values.

Find power factor, kVA, kVAR, phase angle, correction kVAR, current change, and capacitor microfarads from common electrical inputs.