What Size Generator Do I Need For a Power Outage?

What Size Generator Do I Need For a Power Outage

If you’ve ever experienced a power outage, you know how frustrating it can be to go without electricity. A generator can be an excellent investment to ensure that you have power during these situations. But you might be concerned about the generator size, aren’t you?

The size of the generator you need for a power outage relies on the wattage requirements of the appliances and equipment you want to power. Here is a general guideline to help you determine the size of the generator you need:

  • 3000 – 5000 Watts: Refrigerator, lights, and a few outlets.
  • 5000 – 7500 Watts: A Well pump, a sump pump, or an air conditioner.
  • 7500 – 10,000 Watts: Larger home with more appliances and equipment.

In this article, you’ll fetch how to determine the correct size generator for your home or business. So, without further ado, let’s get straight into it.

Table of Contents

Factors To Consider When Choosing A Generator

What Size Generator Do I Need For a Power Outage?

The size of the generator you need for a power outage depends on several factors. Here are some key things to consider when choosing a generator:

Power Output

The power output of a generator is measured in watts. The higher the wattage, the more electrical devices it can power. Before purchasing a generator, make a list of all the appliances and devices you want to power during a power outage.

This will give you an idea of the wattage you need.

Fuel Type

Generators can run on various fuel types, such as gasoline, propane, or diesel. Choose a generator that uses fuel that is readily available and cost-effective in your area.

Noise Level

Some generators can be very loud, so you’ll want to choose one that produces minimal noise. Noise level is usually measured in decibels (dB), and you’ll want to select a generator that produces less than 70 dB.

Run time

Run time refers to the length of time a generator can run before it needs to be refueled. Choose a generator with a run time that meets your needs based on how long you anticipate the power outage to last.


If you plan to move your generator around, you’ll want to choose one that is easy to carry. Look for generators with wheels and handles for easy transport.

Brand And Reputation

You must have to research the brand and read reviews from other customers. Make sure you’re choosing a reputable brand with positive user feedback.


You’ll also need to determine your budget before purchasing a generator. You can get a suitable generator by comparing the prices of different generators and choosing one that fits your budget and needs.

How To Determine The Generator Size You Need?

What Size Generator Do I Need For a Power Outage?

To determine the size of the generator you need, you should consider the following factors:

Calculate Your Total Wattage Requirement

  • Make a list of all the appliances and equipment you want to power with the generator.
  • Check their wattage ratings and add them up to get the total wattage requirement. Make sure to account for the starting wattage of appliances that have electric motors, like refrigerators, air conditioners, and pumps.

Determine The Starting Wattage & Running Wattage

  • Starting wattage is the power required by the appliance or equipment to start up. It is usually higher than its running wattage.
  • Running wattage is the power required by the appliance or equipment to keep running.

Consider The Generator’s Capacity

  • A generator’s capacity is usually expressed in watts and is the maximum power output it can provide.
  • Choose a generator with a capacity that is equal to or greater than your total wattage requirement.

Allow For Some Headroom

  • Choose a generator with a capacity that is slightly higher than your total wattage requirement to allow for some headroom for any additional appliances or equipment you may want to power later.

By considering these factors, you can determine the generator size you need to power your home or business in case of a power outage or to provide electricity in remote locations.

It’s essential to select the correct size generator to avoid overloading the system or underpowering your appliances and equipment.

Related: How To Connect a Generator To Your House?

Tips For Maintaining Your Generator

Proper maintenance of your generator is essential to ensure it runs smoothly and efficiently. Here are some tips for maintaining your generator:

  • Please read the manual: Before operating your generator, read the manufacturer’s manual and understand how to use and maintain it.
  • Regularly change the oil and filters: Follow the recommended oil and filter change intervals specified by the manufacturer. Dirty oil and filters can affect the performance of your generator.
  • Keep it clean: Regularly clean your generator to prevent dirt, dust, and debris from clogging the air filters and affecting its performance. Use a damp cloth to clean the exterior and a soft brush to clean the air filters.
  • Check the battery: If your generator has a battery, make sure to keep it charged and check it regularly. A dead battery can prevent your generator from starting.
  • Inspect the spark plug: A dirty or damaged spark plug can affect the performance of your generator. Inspect the spark plug and replace it if necessary.
  • Use the right fuel: Use the fuel recommended by the manufacturer and avoid using old or contaminated fuel. Stale fuel can cause starting problems and damage the carburetor.
  • Store it properly: If you store your generator for an extended period, drain the fuel tank and carburetor, and keep it in a dry and ventilated area.

By following these tips, you can ensure that your generator runs smoothly and efficiently when you need it the most. Regular maintenance can also help extend the life of your generator and save you from costly repairs.

Related: What Size Generator For House?


Choosing the right size generator for a power outage requires calculating your total wattage requirement and selecting a generator with a capacity of at least 20-25% higher.

Portable generators are a popular choice for small to medium-sized homes, while whole-house generators are ideal for larger homes or those with special power needs.

By choosing the right generator size, you can ensure that your essential appliances and equipment remain powered during a power outage, keeping you and your family safe and comfortable.

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Hi, Welcome to Generatorrookie.com; My name is Shahzad, and I know about generators because I grew up in a country where power outage is very common. I share Tips, How-To, News, and Reviews for the best generators or anything related to generators.

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