Even if it’s just a flicker, power outages are no fun. But when they last indefinitely, they can be inconvenient, annoying, and even expensive if the food in the fridge spoils. Maybe you’ve already thought about some of the advantages of having your own generator. Not only will you need a licensed electrician to install it for you, but you also need to know what size to get! This post will discuss how to determine the right-size generator to power your home!


The size of a generator is measured by wattage. So figuring out the generator you need depends on how much power you need to run everything in your home. You can do this based on your home’s size and typical electric usage, or you can estimate your electric needs by adding up wattages on every household appliance.

It’s important to remember that selecting a generator that’s too small will be ineffective, and could actually damage your appliances. Similarly, one that’s too large will be inefficient and expensive to run. That’s why it’s critical to find the right size.

Since your generator will (hopefully) only be used in emergencies, it’s important to determine the absolute essentials that will continue to need power. That could include things like your HVAC, water pump, stove, refrigerator, lights, or other essentials. Add up the wattage to determine your needs!


The list below can help you figure out what you need. These are only estimates for wattage, but you should be able to find specifics on each appliance’s label or owner’s manual. Once you’ve added up the total, divide by 1,000 to figure the total kilowatts needed for a new generator.

Central Air –  8,000

Gas Furnace – 600

Electric Furnace – 18,000

Electric heat pump – up to 15,000

Baseboard heaters – 225 per foot

Water pump – 750

Gas water heater – 1,000

Electric water heater – 4,500

Computer – 200

TV – 300

Refrigerator – 600

Dishwasher – 700

Microwave – 1,000

Freezer – 2,500

Electric oven – 2,500

Dryer – 5,000

Washing machine – 750

Garage door – 700

Lighting – 500


City Plumbing now has licensed electricians and we’re licensed Cummins generator installers! We can help you with any of your electrical needs, including generator installation. Once you’ve decided what size is right for you, make an appointment online or call us today at (432) 366-2401. Give us a call, and we’ll come running!