What size generator do I need?

If you’re in the market for a generator, you’re probably confused on where to start. Generators come in all shapes and sizes with different features and capabilities that may not be necessary for your needs. Choosing the right size generator for you can get confusing if you’re not sure what to look for.If you’re asking yourself the question “What size generator do I need?” and don’t know how to answer it, you’ve come to the right place. This guide will take a deep dive into the sizing of generators and provide the tools needed to find the generator that’s right for you.

Quick Overview of Key Question

The size of generator you need is determined by the amount of electrical power required to support the items in your home. A professional electrician can help you determine the right generator size for your particular situation.

Assessing Your Energy Needs

Choosing the correct sized generator for your needs can be an overwhelming task due to the many factors that come into play. In order to select the right size generator, you must first assess your exact energy needs. Knowing your overall wattage requirements will allow you to determine the most efficient and powerful generator for your job.

When evaluating your energy needs, consider all of the appliances, tools, and equipment you plan to power with your generator. Calculate their exact wattage usage in order to get a comprehensive view of how much energy you need. A good rule of thumb is to account for at least an additional 25% of wattage over your calculated total in order to ensure that you have enough power available in the event of unforeseen circumstances. This will help to prevent overloads and surges while also providing extra headroom in case of emergency.

Another important factor when assessing your energy needs is to determine if you require service from multiple utilities. If so, then you may need a larger and more powerful generator than if you were only powering one type of utility. As such, it’s important to factor in all potential scenarios when assessing your energy needs.

Finally, think about whether or not conserving energy is important to you. If so, then look into generators with efficiency ratings that meet or exceed your expectations. Such generators may be slightly more expensive but they often pay for themselves over time by reducing fuel costs and other associated expenses.

Ultimately, taking the time to accurately assess your exact energy needs will give you an understanding of how much wattage you truly need in order to find the perfect generator for your requirements. With this information in hand, you can now proceed on to determining your exact generator wattage requirements which is discussed in detail in the following section.

Determine Your Generator Wattage Requirements

Determining your generator wattage requirements should be the first step when deciding what size generator to buy. The wattage requirements depend on the amount of voltage and amperage needed for all of the equipment you plan to power with your generator. To determine the wattage required, add up the rated wattages for each appliance or motor that you want to operate simultaneously.

It is important to keep in mind that motors, including pumps and air conditioners, will draw three - six times more power than their nameplate ratings during startup. This surge could potentially overload a generator if not taken into account. Calculating a surge allowance for motor-driven equipment is not an exact science, but most experts recommend adding 10 - 20% more wattage capacity to account for these possible surges.

When selecting a generator, it is important to factor in additional loads as well as startup current requirements. The running watts are the amount of power that an appliance requires when in use while the starting watts (or surge watts) is the amount of power it needs upon start up. When operating multiple items simultaneously make sure you look out for any overlaps in requirements and avoid redundancies.

Finally, bear in mind that safety should always be the priority when using generators – never connect anything directly to its outlet without having a transfer switch or circuit breaker installed between the generator and your home's electrical panel.

Having properly considered your wattage requirements, you are now ready to move on to calculating the size of your generator.

Calculating the Size of the Generator

When selecting the right generator for your needs, one of the most important factors to consider is size. The size of the generator should be based on the power requirements of all of the items you will be powering with it. If a generator is too small, it won’t have enough power to run all of your devices at once.

There are two different ways to calculate the size of the generator needed: by measuring in watts or by calculating the running and starting wattage. Measuring in watts is usually done for small generators that only need to power a few basic appliances like an electric water heater or furnace. Calculating running and starting wattage typically works best for larger generators that will be used to power multiple devices, as you can ensure that you are accounting for both the amount of energy required for each device when it starts and when it’s running.

If you choose to measure in watts, make sure that you add up all of the wattages from each appliance or device that you plan on running simultaneously. This will give you an estimate of how much power your generator needs to supply at once. Take this figure and compare it with generators available on the market so you can find a unit that can meet your needs.

For calculating running and starting wattage, take into account any tools or electrical equipment you plan on running and their respective start-up requirements, as some devices may need more energy upon startup than others do while they're running. Add both figures together and compare them with different models so as you can identify a model that can comfortably meet your power demands.

No matter which method you choose, accurate calculation is key in finding a generator that meets your needs and avoids voltage dips or power shortages due to insufficient electricity supply. With this knowledge ready, we now move onto how to calculate the watts required for each device in order to correctly choose a generator for your needs.

Calculate the Watts Required for Each Device

Calculating the watts required for each device is an important step when determining which generator you should buy. This number will determine the size of the generator you will need and ultimately help you achieve your desired outcome. Many people make the mistake of underestimating their wattage needs, which could potentially lead to an inadequate generator purchase and possible safety issues.

The best way to calculate the wattage needed is to begin by looking at the individual wattage requirements for every product or device that needs to be supported by the generator. This wattage can usually be found on the item’s label or in its operating manual. To get a more accurate reading it is wise to add 25 percent onto this specified wattage as a buffer. For example, if a fridge needs 500 watts then add 25 percent, which would bring you to a total of 625 watts for this particular appliance.

To get an approximate reading of how much power you need in total, add up all of the required wattages from all devices together. This figure is called the “peak power” and should be used as a guideline when purchasing your generator. Ideally you want to choose a generator with enough power to sustain all required devices at peak power plus additional appliances that may run intermittently at lower wattages such as a freezer or dishwasher.

When calculating your peak power requirement it is important to remember that plugging too many devices into one outlet can cause overheating. This could create a fire hazard and damage the appliances connected, so always strive to spread devices out across multiple outlets using a surge protector and/or extension cords when necessary.

By taking measures such as these into consideration, it ensures not only your safety but also reduces stress on your device and maximizes their performance over time. Calculating the proper wattage required for every device should provide you with enough information to make informed decisions about what type and size generator you should purchase for your specific needs and budget.

With careful calculations now done, there are still other factors that need to be considered before deciding which generator is right for you and this will be discussed in our next section: "Possible Factors To Consider".

Must-Know Highlights

The wattage requirement for each device must be calculated in order to determine what size of generator should be purchased. This can be done by looking at each item's label or manual and adding 25% as a buffer. Taking extra measures such as spreading the devices across multiple outlets with a surge protector, will not only increase safety but optimize performance in the long run. Calculating wattage requirements should equip an individual with enough information to make informed decisions about which generator is best for their specific necessities and budget.

Possible Factors To Consider

When determining the size of generator you require, there are a variety of factors you must consider. First, decide the type of power – either 120 volts or 240 volts – required for your machine. This is usually determined by the type of appliance being powered by the generator and its power needs. If multiple machines are going to be used simultaneously, then it would be important to account for the combined wattage needs from all appliances. It is typically recommended to purchase a slightly larger generator than what is necessary for your purposes so that any extra devices can then be easily added in later on without having to worry about additional power output.

In addition to taking into account the type and amount of appliances using the generator, one should also review the electric load capacity at which they will be operating their generator. Generally, generators run at electric loads between 25-75%. Therefore, if you plan to start multiple machines simultaneously or use large equipment while running your generator, it is best to choose a generator with a higher load capacity than what would typically be required.

Finally, be aware that environmental conditions like temperature and altitude can have an impact on the maximum load capability of your generator as well. High altitudes may require more fuel for generator operation due to air pressure changes; similarly temperatures over 90 degree Fahrenheit require generators with greater fuel efficiency and cooling rates. Understanding these requirements ahead of time will help ensure that you choose a generator compatible with your location and climate conditions.

Leading into the next section:

Now that you understand some general factors to consider when deciding on a generator size, let's look into different types of generators available on the market and how they might best fulfill your individual needs.

Type of Generator

When choosing the right generator for your needs, there are different types of generators depending on the size and power of electricity being generated. The main types of generators available on the market include: portable generators, standby generators and commercial/industrial-class models.

Portable Generators: Portable generators are the most common type of generators used in residential homes and are usually powered by gasoline. They come in a variety of sizes and power outputs, ranging from 2kW to 10kW or even higher. These models are designed to provide temporary power to homes or other sites during outages and are not ideal for permanent or long-term use. Consequently, they are typically less expensive than other models, making them a sensible choice for occasional use.

Standby Generators: Standby generators are larger than portable models, usually offering more than 7kW to up to 50kW of power output, although some commercial grade systems can generate even higher levels. As the name implies, this type of generator is designed to be permanently installed in close proximity to a home or building in order to provide backup power when an outage occurs. Standby generators require more space and installation requirements than portable models and can be quite costly, however they do offer the benefit of automatically providing power when needed, without requiring manual start-up.

Commercial/Industrial Grade Generators: These large capacity units provide some of the highest wattage outputs (from 125kW to over 10MW) and are used for powering industrial applications or businesses that need long term backup power for operations. They may require special permits or qualification criteria for installation and tend to have higher fuel costs due to their larger size.

No matter what type of generator you choose, it’s important to research your options carefully before making any purchase decisions in order to ensure you get the best value for your budget. Now that you know more about the various types of generators and their capabilities, let’s move on to taking a look at installation and use considerations for each generator type in our next section.

Installation and Use of a Generator

When it comes to installing and using a generator, many factors must be taken into consideration. The first step is to determine the size of the generator you will need. This will depend on the type of powered devices or appliances that you wish to use with your generator. It is important to know the power requirements of each device you are planning to power and add up the wattage requirements for all of them. Once you have determined the total wattage requirement for all devices, then you can purchase a generator that meets those needs.

Once purchased, the next step is to install your generator. Depending on what type of generator you select, installation may be as simple as plugging in some cords from the generator to a wall outlet or more complex requiring an electrician for proper connection. If there are no local codes prohibiting their use, portable generators can be plugged directly into a wall outlet with an interlock device. It is always best practice to consult an electrician before beginning installation as local codes may require additional safety equipment in order for proper installation.

The final step when using a generator is making sure that it is properly maintained. All generators should have regularly scheduled maintenance performed on them by qualified service personnel in order to ensure they continue working safely and efficiently. This includes changing the oil, replacing worn parts, and checking all connections including fuel lines and electrical components.

Making sure your generator is installed correctly and well-maintained is essential for safe operation and long-term performance. Being informed and taking steps to make sure your generator will meet your needs and operate safely are important parts of being a responsible owner/operator of a power generating system.

Conclusion: What Size Generator Do I Need?

Now that we’ve looked at factors such as how much electricity a particular appliance draws when turned on, what size generator you need based on these measurements, installation options and necessary safety precautions – it’s time for us to answer the question “What size generator do I need?” In this last section we will explore ways to choose the appropriate generator size for your specific needs.

Conclusion: What Size Generator Do I Need?

When deciding what size generator to purchase, it is important to consider the amount of power you need and the type of appliances or devices that will be powered by your generator. Different types of generators have different wattage output levels, and selecting a generator with too much or too little wattage may result in disappointed parties.

The best way to determine which size generator to buy is to make a list of all the electrical devices you plan on powering with your new generator. Then, calculate the total wattage you’ll need (for appliances and motor-powered tools combined) and select a generator size that can accommodate the combined wattage of all devices and/or appliances.

For audio-visual applications, isolated circuits are often recommended for equipment requiring delicate electronic components such as TVs and laptops. An isolated circuit device allows for an uninterrupted stream of power, protecting delicate electronics from surges or spikes in voltage.

Similarly, portable generators don't require additional components like a fuel tank stove or other (natural gas or propane) container because the casters built into the machine allow for easy transport from place to place.

Ultimately, each person will have different needs for their personal or professional applications, so researching the different types of generators available, considering how much power each machine produces, and understanding power requirements for all intended devices before investing in a particular model is strongly encouraged.


What factors should I consider when choosing a generator size?

When selecting a generator size, you should consider several factors:

1. How much power do you need? Start by calculating the wattage of all appliances, tools and other equipment you will be using at once to find out how much power you will need.

2. What type of fuel does it use? Generators come in different types, with some using gas or diesel and others using propane. Choose a type that works best for your needs and budget.

3. What is the desired range? Think about what kind of range you would like your generator to have and factor this into your selection.

4. Is it easy to transport? Conditions can change quickly, so having a generator that is easy to transport could be a lifesaver. Check the size, weight, and portability before making a final decision.

5. Is there adequate ventilation? Make sure the area around the generator is well ventilated by checking local regulations or consulting a professional if needed.

6. Is it safe? Generator safety should always be considered in order to avoid any potential hazards. Be aware of common risks such as electrocution, carbon monoxide poisoning and fire hazards when using a generator.

How do I know how much power my home needs?

The best way to know how much power your home needs is to calculate the wattage of all of your appliances and procedures that will be running at once. You'll need to total up all the watts of the various items you'll be connecting to your generator, from lighting and entertainment systems to air conditioning and refrigeration. From here, you can determine what size generator you need by multiplying the total watts by 1.2 (which gives a bit extra for startup surges) and choosing a unit that falls within that wattage range. Additionally, it's always a good idea to choose a generator with more than enough power than estimated — this way if you add any new appliances or procedures in the future you won’t have to worry about not having enough power for them.

Will I need to install an external power switch for the generator?

Yes, installing an external power switch for the generator is recommended. Generators should be connected to an external power switch and isolator when used in homes or businesses. This ensures that the generator can be easily and safely switched off if necessary. Additionally, connecting to an external power switch and isolator will prevent the risk of electric shock or electrocution if a connection between the generator and internal wiring is made by accident.