Home Generator Sizing Guide

How to figure out what size generator you need

What you would like to power during an outage will determine the size of generator you need.  The size of your home is not a factor

The simple solution is to size a generator to match the maximum power the utility company provides you.  But, unless you are tripping circuit breakers, you are never using all that is available.   So, many reduce the generator size to one that can power what you need instead.   Do you want to use everything simultaneously or take turns using the oven and dryer, for example?   This chart will give you a rough idea of what you can power with different size generators. 

Size

Application

Suitable For...

6 kW - 8 kW

Necessities

• Most homes don't use more than 5 kW / hr on average. 

• Power your fridge, freezer, water pumps, fans, microwave, kettle, a single stove element, coffee maker, and all your lights. 

• Very common for cabins, cottages, off-grid homes and basic necessities for day to day living

• Superior to portable generators. 

10 kW

Necessities Plus

• Powerful enough for window type air conditioners but not for large central air.

 

• Commonly used in homes that don't need to use central air conditioners, but you can easily power a few window air conditioners

12-13 kW

Suitable For Most Homes

• Enough power for most homes.

• Using all your heavy appliances at the same time may not be possible. 

20-22 kW

Whole Home

• You have enough power and the ability to carry on as if an outage never happened.

• In extreme conditions, it might not be enough for the oven, stove and central air plus dryer all at the same time.

25 kW

Large Home

• Better solution for homes with large or multiple central air conditioning or homes that rely on electric heat.

30 kW

Large Home 

Two-Family Home

• Typical 400 Amp Homes 

Disclaimer: The guide above was created to help you determine the size of generator you need to provide power to appliances and household items in the event of a power outage. It’s important to remember that you wouldn’t be running everything at the same time.