TrueSource Generators Horizontal 2

Welcome to our Generac Generator Sizing Calculator!

For the most accurate generator sizing, call us at 1-855-502-3592. Or, if you prefer, use our easy online calculator to determine the right generator size for your home. Whether you need expert advice or quick results, we're here to help you find the perfect fit.

House Icon

Step 1: Home Details - What is the Size of your Home?

AC Icon

Step 2: Central Air Conditioner Size

AC units come in several sizes depending on their BTUs or Tons. Since central air conditioners typically use more wattage than any other appliance in your home, you will want to make sure you get a generator that can handle the load.
Plug Icon

Step 3: What Do You Want To Power?

Choose what your power needs are clicking below. Select whole house if you want everything to run at the same time during a power outage.
Whole House
Customize

Whole House

Selecting whole house provides a backup generator recommendation based on your home's size and corresponding outlets and lighting requirements and assumes natural gas appliances in the baseline calculation. If your home has electric appliances like an electric range, electric clothes dryer, electric water heater, etc., you can add these items below to accurately reflect your home's specific backup power needs.

Customize

Use this option if you want an emergency back-up generator without powering your entire home. Be sure to select each electrical appliance you wish to have backup power for in your home below.
Gear Icon Essentials
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1
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AC Tonnage 1
1
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AC Tonnage 2
0
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Window AC
0
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Well Pump
0
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Electric Water Heater
0
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Heat Pump
1
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Gas Furnace
1
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Refrigerator
1
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Sump Pump
Appliance Icon Appliances
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1
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Electric Oven/Stove
0
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Gas Oven/Stove
1
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Microwave
1
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Dishwasher
1
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Garage Door
1
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Electric Dryer
Shield Icon Extras
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1
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Computer
0
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Hot Tub
0
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Sauna
0
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Pool
1
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Security
Lightings and Outlets
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0
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Bedrooms
0
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Office
0
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Living Room
0
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Dining Room
0
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Kitchen
0
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Bathroom
0
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Basement
Appliances
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0
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Refrigerator
0
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Electric Dryer
0
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Electric Oven/Stove
0
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Electric Cooktop
0
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Garbage Disposal
0
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Freezer
0
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Electric Water Heater
0
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Garage Door
0
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Microwave
0
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Dishwasher
0
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Washer w/Gas Dryer
Extras
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0
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Gas Furnace
0
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Boiler
0
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Window AC
0
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Heat Pump
0
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Sump Pump

Don't see an item you need? Add Your Own

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Add Item
Calculate Size

Recommended Models

This sizing tool is intended for estimating purposes only. This tool assumes that you will use load management and will not run all appliances at the same time. Transfer switches should be sized to your particular application. We recommend having an licensed electrician or certified installer verify your specific electrical requirements before purchasing. All installations must be performed by a certified electrician in accordance with local codes to maintain manufacturer warranties.Call Our Experts: 1-855-502-3592