Choosing The Right Size Generator

Power outages are becoming increasingly common, with the average American experiencing 8 hours of unplanned power loss each year. A reliable generator is essential for ensuring your comfort and safety during these times.

But selecting the right size generator can be a daunting task, as factors like wattage requirementsfuel type, and desired usage all play crucial roles in making an informed decision.

In this blog post, we’ll discuss the importance of choosing the right generator size, explore different factors to consider when purchasing one, and guide you through taking inventory of your individual needs so that you can confidently select the perfect generator for your home or business.

Key Takeaways

  • Choosing the right size generator is crucial for ensuring backup power during outages, emergency situations, and efficient energy usage.
  • Factors to consider when choosing a generator include wattage requirements, fuel type, physical size, noise level, and the type of generator that best suits your needs.
  • Understanding starting, running + surge wattage is important in selecting the best – suited generator for your home or business.
  • Calculate total wattage needs by taking inventory of all appliances/devices that need power during an outage/emergency.
Generator Power - Wattage Calculator

Importance Of Choosing The Right Size Generator

Choosing the right size generator is critical for ensuring backup power during outages, emergency situations, and efficient energy usage.

Power Outages

Power outages are an unavoidable reality of modern life, affecting millions of Americans every year. On average, U.S. residents experience around 8 hours of blackouts annually, and this number is expected to rise due to the increasing frequency of major weather disasters and an aging electrical infrastructure.

During a blackout, not only do we lose access to essential appliances like refrigerators and lights, but our heating and cooling systems also cease to function – turning homes into uncomfortable living spaces during extreme temperatures.

For families with medical equipment that relies on electric power or for those who work from home, being left in the dark can mean serious health risks or loss of income.

Emergency Situations

In emergency situations, having the right size generator can be critical in providing you with essential power to keep your household running and ensure your safety.

One time during a particularly severe storm in my area, my neighbors lost power for days. Fortunately, they had invested in an appropriately sized generator that provided them with sufficient electricity to run vital appliances while waiting for the power grid to be restored.

Efficient Energy Usage

Efficient energy usage is paramount when selecting the right size generator for your needs. By investing in a generator that provides just enough power to cover your critical appliances and devices during an outage, you’ll not only save on fuel costs but also reduce unnecessary strain on the generator itself.

One way to ensure efficient energy usage is by choosing an inverter generator rather than traditional portable generators. Although these may come at a slightly higher price point initially, they offer numerous benefits like quieter operation and improved fuel efficiency – meaning you’ll get more bang for your buck over time.

Factors To Consider When Choosing A Generator

Consider several factors when choosing a generator, such as wattage requirements, fuel type, physical size, noise level, and the type of generator that best suits your needs.

Wattage Requirements

When choosing a generator, one of the most important factors to consider is wattage requirements. This means calculating the total amount of power needed to run all appliances and devices that you want to use during an outage or event.

It’s important not just to consider how many watts each device uses but also whether it requires additional starting watts when first turned on. For example, a refrigerator may only need 800 running watts, but it could require 2,200 starting watts when powering up.

Fuel Type

When it comes to choosing a generator, the type of fuel you use can play an important role in determining its size and power output. Gasoline generators are popular and can produce up to 3,500 watts of power, making them suitable for portable use or running essential appliances during a power outage.

Propane generators are another option that provides longer run times but may require additional installation costs like purchasing a fuel tank. Natural gas generators are recommended for whole-house backup systems due to their availability and cost-effectiveness compared to other fuels like diesel.

Physical Size

One crucial factor to consider when selecting the right size generator for your home is its physical size. Generators come in different sizes, ranging from small recreational models to large standby units that are capable of powering an entire house.

Larger generators often produce more noise and require ample space for installation, while smaller generators may be more compact and easier to maneuver.

It’s also worth noting that portable generators should only produce enough power for the appliances you want to use, so choosing the correct wattage based on anticipated needs is critical.

Additionally, manufacturers recommend keeping running generators at least 20 feet away from your house or any structure due to concerns about carbon monoxide poisoning and fire hazards.

Noise Level

It’s also important to consider the noise level of a generator when choosing one that fits your needs. Some generators can be loud and disruptive, which could be an issue in residential areas or during camping trips.

Inverter generators are generally quieter than traditional ones, making them a great option for those who need power but want to minimize noise pollution.

For example, the Honda EU2200i is known for being extremely quiet with a noise rating of 48-57 decibels (dB).

Type Of Generator

There are three main types of generators available: portable, standby, and inverter. Portable generators are ideal for powering appliances during power outages or while camping or tailgating.

Standby generators automatically turn on when the power goes out and can provide backup power to an entire house or business. Inverter generators offer fuel efficiency and quiet operation but are typically more expensive than other options.

I recommend considering how often you’ll need to use your generator as well as what appliances you want to power before choosing which type is right for you.

Understanding Starting, Running, And Surge Wattage

One of the most important things to consider when choosing a generator is understanding starting, running, and surge wattage. Starting wattage refers to the amount of power needed to start an appliance or device, while running wattage is the amount of power required for it to continue operating.

Let’s say you have a refrigerator with a starting wattage of 1,200 watts and a running wattage of 700 watts. If there’s also an air conditioner with a starting wattage of 3,000 watts and a running wattage of 1,500 watts in your home circuitry panel then you might need at least an 8000-watt generator.

It’s crucial to factor in these different types of power demands based on your household needs before settling down for any one particular size or capacity generator.

How To Calculate Your Total Wattage Needs

To determine the right size generator for your needs, it’s crucial to calculate your total wattage requirements by taking inventory of all appliances and devices that need power during a blackout or emergency.

Inventory Of Appliances And Devices

Before selecting a generator, it is crucial to take inventory of all the appliances and devices that need power during an outage. This includes items such as refrigerators, freezers, microwaves, and HVAC systems.

Determining the wattage requirements for each appliance can be done by checking their labels or using a formula to calculate watts based on volts and amps.

Keep in mind that some appliances require additional starting wattage, such as refrigerators needing up to 2,200 watts to start up. It’s also important to note that not all appliances can be powered by a generator, including sump pumps and HVAC units.

Calculating Total Wattage

To determine the appropriate size generator for your home or business, you need to calculate the total wattage required by adding up all of the running watts needed and three times the starting watts.

For appliances with motors, like refrigerators and freezers, you need both running wattage and starting wattage. However, items like light bulbs only require running wattage.

For example, a refrigerator might need 700 watts of running power but require another 2100 watts of starting power when its compressor turns on. A window air conditioner unit rated at 1800 watts may also require an additional 5400-watt surge upon startup before settling into its normal operating load.

Types Of Generators

Portable generators are the most common type of generator, providing reliable power for camping trips and outdoor events. Standby generators are designed to provide backup power during an outage and can be connected directly to a home’s electrical system with an automatic transfer switch.

Portable Generators

Portable generators are a popular option for those who need backup power during an outage. These generators range in power production from 1,000 to 3,500 watts and can typically power small appliances and electronics with standard plugs.

However, it’s crucial not to overload your portable generator by using too many high-wattage devices simultaneously. To prevent carbon monoxide buildup that can occur when using gas-powered portable generators indoors or in enclosed spaces outdoors, Consumer Reports recommend only opting for models with CO safety technology built-in.

Standby Generators

If you experience frequent and lengthy power outages, you may want to consider investing in a standby generator. These generators are permanently installed outside your home and automatically turn on during an outage, providing backup power to your entire house.

While they can be a pricier option, starting at around $5,000 or more, they offer peace of mind and convenience during an emergency. With a standby generator, you won’t have to worry about losing access to essential appliances like refrigerators, heating systems, and sump pumps during extended outages caused by severe weather or other disasters.

Inverter Generators

Inverter generators are a newer and more advanced type of generator that provides efficient, clean power. These generators work by converting the raw output of the generator into an alternating current (AC) signal, then back to direct current (DC), which is cleaner and safer for electronic devices.

Inverter generators are known for being quiet and fuel-efficient compared to traditional models. They are great options for powering sensitive electronics while camping or tailgating, but they also have enough power to provide backup energy in your home during shorter outages.

Choosing The Right Generator Size Based On Your Needs

To choose the right generator size, match its capacity with your wattage requirements and consider factors like frequency of use and power needs.

Matching Generator Capacity With Wattage Requirements

To ensure that your generator can power all of the appliances and devices you need during a power outage, it is important to match its capacity with your wattage requirements.

For example, if your refrigerator needs 800 watts and your HVAC unit requires 3,000 watts to start up and 1,500 running watts – totaling 4,300 watts – then you would need a generator with a capacity of at least 5,000 watts.

It’s important not to exceed this number when selecting a generator size or risk damaging both the appliances and the generator itself.

Considering Frequency Of Use And Power Needs

It’s important to think about how often you’ll be using your generator and what kind of power needs you have. For those who experience frequent or prolonged power outages, a home standby generator or large inverter may be the best option.

On the other hand, if you only experience occasional outages or need a generator for recreational use, a small portable or inverter generator might be more practical. These units are typically lightweight and easy to transport but may not have as much power capacity as larger models.

Generator Safety Tips

As a generator specialist, I understand how important it is to keep your family safe during a power outage. Here are eight safety tips to remember when using a generator:

  1. Always read and follow the manufacturer’s instructions carefully.
  2. Never operate a generator indoors or in an enclosed space, including garages and crawl spaces.
  3. Place the generator on a flat surface in a well – ventilated area away from windows, doors, and vents.
  4. Use heavy – duty extension cords designed for outdoor use and check them regularly for damage.
  5. Never fuel your generator while it is running or hot – wait until it cools down before refueling.
  6. Install carbon monoxide detectors in your home and ensure they are working correctly.
  7. Apply stabilized gasoline to the fuel tank to prevent gumming up and store fuel away from living spaces.
  8. Turn off all appliances connected to the generator before shutting down the unit.

Remembering these safety tips will help ensure that you have peace of mind while using your generator during emergencies such as blackouts or storms. By prioritizing safety, you can protect yourself and your loved ones from harm caused by carbon monoxide poisoning or other hazards associated with improper use of generators.

Frequently Asked Questions About Generator Sizing

What size generator do I need for my house? (Chart included), what size generator do I need for my RV, and what’s the difference between watts and amps are some of the most common questions people have when it comes to choosing the right size generator.

What Size Generator Do I Need For My House? (Chart Included)

To help determine the ideal generator size for your house, we’ve put together a handy chart showcasing the wattage requirements of various essential appliances and devices. This should give you an idea of how much power you’ll need from your generator. Refer to the chart below to make an informed decision.

Appliance/DeviceRunning WattageStarting Wattage
Window Air Conditioner600-15001000-3000
Sump Pump800-12002000-3000
Furnace Fan300-900800-2400
Electric Water Heater3000-45000
Washing Machine500-1500800-1800

Keep in mind that these numbers are approximate and can vary depending on the specific appliance or device. It’s crucial to ensure your generator has the capacity to handle both the running and starting wattage demands of your home.

What Size Generator Do I Need For My RV?

If you’re planning on taking your RV out on a road trip, it’s essential to have the right size generator to power all of your appliances and devices. To determine the size generator for your RV, consider the wattage requirements of the appliances you want to use.

It’s important to note that sump pumps and HVAC systems cannot be powered by an RV generator. Additionally, smaller recreational inverters are lightweight and easy to store but have limited power capacity.

Mid-sized inverters can only power 110-volt items with standard plugs.

What’s The Difference Between Watts And Amps?

Understanding the difference between watts and amps is crucial when choosing the right size generator. While amps refer to the electrical current flowing through a circuit, watts indicate how much power that current carries.

Appliances with motors require both running wattage and starting wattage, which refers to the initial jolt of energy required to start them up before settling into their regular operating level.

For example, a refrigerator may require 6-8 amps while running but could need up to 2,200 starting watts.


Choosing the right size generator is crucial for ensuring you have backup power during outages or emergency situations. It’s important to consider factors such as wattage requirements, fuel type, physical size, and noise level when selecting a generator.

Calculating your total wattage needs is also necessary to match generator capacity with your power requirements. Remember to prioritize safety by selecting generators with CO safety technology and following proper installation and maintenance procedures.

With the variety of generator types available in the market today, it’s easy to find one that fits your specific needs and budget.


1. How do I determine the right size generator for my needs?

The best way to determine the size of generator you need is by calculating your power requirements, taking into account all appliances and devices that will need to be powered during an outage. A professional electrician can assist with this calculation.

2. Can a generator produce too much power for what I need?

Yes, purchasing a generator that is too large may result in more expense upfront and potentially waste additional fuel throughout prolonged use.

3. What are some factors to consider when choosing a generator size?

Some important factors include the total wattage needed, run time required, type of fuel used by the unit (gasoline vs propane), as well as any specific safety or efficiency features required for unique applications.

4. Are there certain brands or models of generators that are better suited to specific purposes?

While many high-quality manufacturers offer portable generators suitable for many different applications – each model unique advantages such as increased compactness/drivability or even alternative energy sources like wind turbines etc., so it’s important conduct research beforehand based on individual goals before making final purchase decisions

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I'm Wayne. I have worked in the construction industry for many decades and have had the opportunity to work with various equipment and portable generators. I've also written extensively about both subjects. I spend time with my family when I'm not writing or working in construction.

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