Sam Gorman

Find battery C-rate, current, run time, capacity, and a buffered label current check from common battery specs.

Estimate battery backup time or battery size from load watts, voltage, efficiency, usable battery percent, and battery count.

Convert Ah, mAh, Wh, kWh, and volts, then estimate usable battery energy and runtime from load watts.

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.