How to Estimate Energy Consumption

If you’re trying to manage your electric expenses with careful attention to your habits and overall energy consumption, eventually it is a good idea to run an energy inventory and figure out exactly how much your appliances are consuming. It’s also helpful if you’re interested in buying a new appliance.

Here’s how to estimate energy consumption for your appliances:

Use the formula (Wattage x Hours Used Per Day) / 1000 = Daily kWh consumption

Seem complicated? Let’s simplify. If you have an appliance that has a wattage of 1000, and you use that appliance 8 hours a day (an extreme example), you would multiply 1000×8 to get 8000, and divide that by 1000. That figure would be your daily kWh consumption, 8 in this example. Multiply this by the number of days every year you use the appliance and you have a simple way of determining your annual kWh usage!

You can find the wattage for each of your appliances printed on the bottom or back of the appliance. The number printed is the maximum wattage it would draw, so it will be used as a conservative estimate. Most appliances have a range of power options you can use, such as volume on a radio, so you won’t always be using the maximum wattage.

To get an idea for what type of wattages you can expect, here are a few examples:

  • Dishwasher (1200-2400)
  • Microwave (750-1100)
  • Refrigerator (700-800)
  • Water heater (4500-5500)

Your appliances’ wattages may vary. Make sure you look at each individually. If an older appliance seems rather high, it’s probably time to replace it!