How do you calculate energy use per kilowatt hour?

Energy use in kilowatt-hours is determined by multiplying the number of hours appliance operates by its rated power in kilowatts. We then multiply the electricity cost per kilowatt hour to calculate what it costs to keep the appliance running. Thus, we use the following formula:

How do you calculate kilowatt-hours?

One kilowatt-hour is equal to how much energy that would be used by keeping a 1000 W appliance running for 60 minutes, so for example, if you left a 50 W appliance running, in 20 hours it would use 1 kWh of energy. Energy use in kilowatt-hours is determined by multiplying the number of hours appliance operates by its rated power in kilowatts.

Why are kilowatts-hours used as a measurement of energy?

The reason that kilowatts-hours are typically used as a measurement of energy rather than watt-hours is simply because of scale: the amount of energy a typical household in the United States uses in a year is on the order of millions of watts, so it is easier to discuss in terms of kilowatt-hours instead.

How do you convert watts to kilowatts?

This is typically mentioned on the device label or in its manual. It’s usually given in watts (W). If it’s in kilowatts (kW), that’s even better since we will be using kilowatts-hour (kWh) for the calculation. If the consumption is given in watts, you’ll need to convert it to kilowatts by dividing by 1,000.