What Size Generator Do I Need? 【Best Size Guide】

What Size Generator Do I Need?

If you are looking for a generator and wondering what size you need, then it is obvious your house is facing a power outage occasionally or commonly.

It is common to ask what size generator you need for your house or how much power supply is required to run the entire house’s power because you are not an electrician and still need all answers.

We will give you a thorough answer to every question you have in your mind.

Moreover, we will mention some important things that you should follow to get the job done professionally.

What you should know before buying one:

As you are not a professional and not an electrician, you need to know something before buying a generator. First of all, make a list of all the things you want to run when the power runs out. After making a list, calculate how much power those items or appliances cost while starting and running.

Make two separate lists that include the power watt of all the appliances costs while starting and running.

In addition to these lists, you need to know when the power outage happens.

That means, does it run occasionally or commonly after every few months. Moreover, make sure how many appliances you want to run when there is a power outage.

Most users care about only a few, including a refrigerator, freezer, and AC, while the rest want to run all the appliances. Now you can head toward the next step.

How many types of generators are there?


The generators are categorized according to their power supply to provide to the house. Mainly three types are low power, medium, and high-power generators.

So, how would you know which generator you should consider? Well, it entirely depends upon your house’s power requirements.

That’s why we have categorized them into three types that will give you a complete idea.

Common Power Outage

If your power runs out commonly, you definitely need to invest more money to buy a high watt power generator to run the whole house every other week month. These generators are mainly portable, have a large inverter, and home standby.

You can just connect the output to the circuit. They will run your house’s all appliances including refrigerator, freezer, water heaters, AC, and more like these.

These generators are required commonly in areas where natural disasters like ice storms, hurricanes.

Since the power supply is high, we recommend consulting a professional electrician to set up the generator. It can be risky, so don’t do it by yourself.

Occasional Power Outage

You don’t need to buy a costly generator which supplies high power to the house. As the power outage is occasionally, the generator will be used occasionally. That’s why we recommend an average or low power generator.

Since you don’t want to put the home on standby under these circumstances but still, you need a large inverter that should be portable as well.

All you need to do is buy an average generator and put it in the garage until the power runs out. Once it outages, connect the portable generator, and it’s all done.

Rare Power Outage

In some areas where power outages once or twice the whole year, they need to keep everything running anyway. In such a case, we recommend a midsize power generator that should be recreational as well.

You should never spend $12,000 on a generator that will be used once or twice a year. Still, consider buying a portable generator, but if you don’t, there is an exception.

This generator type usually manages to run an AC, fridge, and any other appliance like these.

How to calculate the power needed?

First of all, make sure you are using the power unit W(Watt), which is commonly used to measure these cases. As you already have made a list of appliances you want to run while the power outages.

Calculate the power that will cost to run all those appliances. As you already have made two separate lists of starting and running power of appliances. It is essential to mention the need for these two separate lists.

All the appliances take more supply when they start to run, and when they start running, the power falls. For example, if a clothing dryer takes 5,400 watts power to run, it must cost nearly 6,750 watts to start.

For this reason, you need a generator that follows the total cost of watt required to run all the appliances.

What Precautions are Needed?

Don’t ever set up the high-power generator by yourself.

Always consult not only an electrician but a professional electrician to do this job. To set up the generator, keep at least 20 distance from the house. Keep the exhaust away from AC, doors, and windows.

Only consider the portable generators that automatically shut down in the case CO builds up to dangerous levels in an enclosed space.

What unit to use while calculating power?

Mainly Amperes (A) and Watts (W) are two main units used to measure the power. So, we recommend you to calculate in any of these two units.

The reason is that most of the appliances you will buy will show power in these two units.

But for more convenience, use only watts that is an internationally used unit. If some of the appliances show power in Amps, simply convert the power into watts. Multiply amps by 120, and you will get results in watts.

To Sum Up

A generator that generates the power of around 1,500 watts is enough for camping use. For house use, on average, you need 10,000 watts of power or more. These are the rough estimates, but for exact figures, you should calculate the power need following all the processes mentioned above.

Once you know the exact requirements, you will have a better experience with your generator. Don’t ever waste a lot of money on heavy generators rarely used and never buy a cheap generator for high power requirements.

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