A kilowatt hour (kWh) is a unit of electrical energy and can be defined as the energy consumed by a 1 KW appliance for one hour. This unit is also used to measure electricity consumption as shown on your bill. To estimate the electrical for a device in your home, multiply the kilowatt rating of that device by the service time. For example, a 60W bulb that operates for 200 hours in a month will consume 12 kilowatt-hours of electricity as shown in the calculation below.
Example: Rating of a 60W Bulb = 0.06KW
Number of hours used per month: 200 hrs kWh consumption = 0.06 x 200=12 kWh