Surprisingly enough, there is more to your utility bill than just what you owe. Discerning between specific measures can help you better understand your building and uncover opportunities to save. Today we’re going to help you decode your energy bill by breaking down the differences between a kilowatt (kW) and a kilowatt hour (kWh).

You will notice that your bill charges you based on the amount of kilowatt hours used, but what exactly is a kilowatt hour? The textbook definition of a kilowatt hour is a measure of electrical energy equivalent to a power consumption of 1,000 watts per one hour. To make this less scientific, let’s think of a microwave. For example, you go to the store and buy a 1,000-watt microwave. Over the course of one week that microwave runs for a total of one hour. This energy use is equal to one kilowatt hour.

What is the difference between a kilowatt and a kilowatt hour? A kilowatt hour measures energy and a kilowatt measures power. So, while a kWh reflects the total amount of energy used, a kW reflects the rate at which this energy was consumed.

Why does this matter? It may seem trivial to debate between two very similar units of measurement but understanding these measurements can help you identify where you’re losing the most energy. For example, lighting can eat up a lot of energy, which is why LED upgrades are so popular. The bulbs offer a lower wattage with even more light.