The

**kilowatt hour**(symbolized**kW**⋅h as per SI) is a composite unit of**energy**equivalent to one**kilowatt**(1**kW**) of power sustained for one**hour**. One watt is equal to 1 J/s. One**kilowatt hour**is 3.6 megajoules, which is the amount of**energy**converted if work is done at an average rate of one thousand watts for one**hour**.Similarly, you may ask, what is the difference between a kilowatt and a kilowatt hour?

A

**kilowatt-hour**is the amount of energy equivalent to a power of 1 kilowatt running for 1 hour. If you leave a 100 Watt light bulb on for 1 hour, you've done gone and used up 100 watt-hours. But your electric company will bill you by the**kilowatt-hour**, so you'll get a bill for .1**kWh**, multiplied by your per-**kWh**rate.How do I calculate kWh from kW?

**Method 1**

**Estimating Kilowatt Hours from Appliance Labels**

- Find the wattage on the appliance label.
- Multiply wattage by hours used each day.
- Divide the result by 1,000.
- Multiply your answer by the number of days you're measuring.
- Multiply by the cost of electricity per kWh.

How many watts is a kilowatt hour?

Convert to

**Kilowatts**. But electricity is measure in**kilowatt hours**on your electricity bill. Since we know that 1**kilowatt**is equal to 1,000**watts**, calculating**how many kWh**a particular device uses is as easy as dividing by 1,000.