Understanding the basics about kWh can help you balance your energy consumption and potentially reduce your power costs. Learn how to monitor your electricity usage and calculate the costs with our complete kWh guide.

What Is a kWh of Electricity?

Let’s start from the beginning—not from when electricity was invented, but with a kWh definition. In order to understand what a kilowatt-hour is you’ll need to understand kW vs. kWh:

  • A kilowatt (kW) is 1,000 watts of power.
    • A watt is a unit of power that measures how many joules (units of energy) an appliance uses per second.
  • A kilowatt-hour (kWh) is the amount of energy an appliance consumes on an hourly basis.

Your kilowatt-hour consumption factors in how many watts your appliances use and how often you use them. For example, if you have a 1,000-watt clothes dryer and run it for an hour, you are consuming one kilowatt-hour or 1 kWh.

The equation for figuring out how long you would need to use an appliance to equal 1 kWh is fairly simple:

1kWh Appliance’s wattage (in kW) = Time using appliance (in hours)

Let’s take another stab at understanding kilowatt usage, but using different examples of high- and low-wattage household appliances (we’ll do some more practice calculations later):

  • Lower wattage: If you are using a 100-watt device, such as a light bulb, you would have to keep it on for 10 hours to equal 1 kWh of energy.

          1kWh 0.1kW = 10 hours

  • Higher wattage: If you are using a 2,000-watt appliance, such as an oven, you only need to use it for a half an hour to rack up 1 kWh.

          kWh 2kW = 0.5 hours

As you can see, the power you use daily can quickly add up to 1 kWh when you are dealing with high-wattage devices and appliances in your home.

Examples of 1 kWh Usage

To help you better understand what a kilowatt-hour of electricity is, we’ve come up with some examples of 1kWh usage around the house. Remember, wattages vary depending on the type of appliance. Below, you’ll find estimates of how long it takes some common household items to reach the 1 kWh mark:


  • LED TV (30W): With a 30-watt LED TV, you could binge-watch your favorite shows for 33 hours and 20 minutes before reaching 1kWh of energy.
  • Laptop (50W): A 50-watt laptop can keep you working overtime for 20 hours.
  • Electric blanket (200W): You can cozy up with your 200-watt electric blanket for 5 hours.
  • Washing machine (500W): You could do a couple of loads of laundry in the 2 hours it would take for a 500-watt washing machine to use 1kWh.
  • Microwave (1,000W): You can use your 1,000-watt microwave for an hour—popcorn anyone?

Let’s look at some examples of how long it takes higher-energy appliances to use 1 kWh:

  • Dishwasher (1,500W): A 1,500-watt dishwasher can run for 40 minutes before using 1kWh.
  • Oven (2,000W): A 2,000-watt oven can roast your dinner for 30 minutes.
  • Clothes dryer (3,000W): A 3,000-watt clothes dryer can use 1kWh of energy in just 20 minutes!
  • Hot water heater (4,000W): To reach 1kWh, a 4,000-watt water heater taps out at 15 minutes. Keep those showers short!
  • Central air conditioning (5,000W): It takes a 5,000-watt central A/C unit 12 minutes to use 1 kWh of energy.

How to Calculate kWh of Your Appliances

To calculate the kWh of your appliance, find the appliance’s wattage (generally on the label) and estimate how many hours you use it daily. You can calculate the kWh per day by multiplying the watts by daily hours of use. Remember, one kilowatt equals 1,000 watts, so you need to divide your wattage by 1,000 to convert to kilowatts.

Use this simple equation: = kWh per day

In this next example, let’s take a 2,000-watt oven and determine how many kWh per month if we use the appliance for two hours each day:

  1. Calculate the kilowatts by dividing wattage by 1,000:

    2,000 watts 1,000 = 2 kW

  2. Multiply kW by hours of daily use:

    2kW X 2 hours = 4 kWh per day


  3. Estimate the total energy usage for a month (30 days):

    4 kWh X 30 days = 120 kWh per month total

Make a list of appliances that you use in your home and do the same calculations. Now that you have mastered what is a kWh of electricity and how power is measured in a month, you can start making some adjustments to save on energy consumption in your home.

How Do Electricity Companies Calculate Monthly Costs?

Utility companies measure your kWh with mechanical or digital meters right outside your home. Newer digital meters use high-frequency signals to send data to the utility companies about your electricity usage.

Once companies establish your monthly kWh energy consumption, they simply multiply the kWh by Alberta’s current regulated rate. Using the example from above and a regulated rate of $0.07/kWh, let’s figure out what the monthly cost estimate would be for the 2,000-watt oven:

120 kWh X $0.07/kWh = $8.40 per month


Not surprisingly, heating your Alberta home takes up a whopping 61 percent of your estimated energy usage, according to Natural Resources Canada. However, learning what a kWh is and how you can reduce your annual costs in other areas can help balance the added expense of heating your home throughout the year.

How Do I Monitor My Electricity Usage?

Perform a thorough review of your electric bill to assess your monthly electricity usage and costs. Now that you know what a kilowatt-hour is, you can dig a little deeper to see which appliances are using the most electricity.

Think about installing a home energy monitor, which will provide you with detailed tracking of your household electricity consumption. Certain home energy monitors are wireless and can even track energy usage by appliance. Furthermore, some home energy monitors allow you to set up “High Usage” alerts if you’re trying to be extra vigilant about your energy consumption.

Ways to Reduce Energy Costs

You can lower your electricity bills by simply following a few best practices: Get into the habit of turning off the lights when leaving a room and turning your heat down when you leave the house or are asleep.

Use these other easy ways to start reducing your energy costs today:

Choosing Energy-Efficient Appliances

Investing in energy-efficient appliances may help you save money in the long run. Simply look for the yellow ENERGY STAR® symbol on the appliance you’re thinking about buying. These certified energy-efficient appliances perform at the same or better level as other products on the market. Use your kWh calculations to really compare the savings.

To find out more about the ENERGY STAR® products available in Canada, check out Natural Resources Canada for a list of energy-efficient appliances and how much you can potentially save on appliances like:

In addition to energy-saving products, you can also invest in an energy usage monitor that can track your consumption and let you know when to replace appliances.

Utilize Our Resources

As your Alberta power company and neighbour, we’re here to offer guidance on home improvements to help lower your bills and energy costs. From assessing your Alberta electricity needs to learning what a kilowatt-hour is, we’re here to help you meet your home and energy needs. Contact us anytime at 1.866.420.3174.