How to Calculate Electricity Usage and Cost
Electricity use is straightforward to estimate when you know an appliance's power, operating time, and the price you pay per kWh. This guide explains watts, kilowatts, kilowatt-hours, the core formulas, worked appliance examples, and direct cost calculations when your kWh usage is already known. Power and energy use are different quantities Watts (W) and kilowatts (kW) describe power: the rate at which a device uses energy at a given moment. Kilowatt-hours (kWh) describe energy used over time. 1 kW = 1000 WEnergy, kWh = Power, kW × Time, hours A 1500 W appliance has a power rating of 1.5 kW. ..