What Size Generator Do I Need For A 1500 Square Foot House?

A usual 1500 sq. ft home requires about 5 to 8 kW of power with all the necessary appliances. If you are using a standby generator then you should get one in the range of 7-15 kW. An inverter generator must have a size of about 7 kW. Whereas the solar generator will provide much less around 1-5.1 kW, which is not sufficient enough. Last but not least, a portable generator must provide around 7 – 12 kW. Also, choose a generator with 10 to 20% increased capacity to have available wattage in your reserve. 

So, what size generator do I need for a 1500 square foot house?

Well, the answer depends on the home appliances and additional power requirements. Read on to know the details.  

How to Understand Generator Size for a 1500 square foot House?

Generator Size for a 1500 square foot House
Source: incontrolwi.com

To understand the generator size requirement for a 1500 sq ft house, you’ll need to calculate some factors. 

  • List all of your home appliances that will run on the generator such as TV, HVAC, refrigerators, laptops, stoves, heaters, microwaves, garage doors, etc. 
  • List the wattage requirement for all the appliances. Remember to pay attention to starting watts (surge wattage) and running watts for the appliances. 
  • Now, add up the wattage of the appliances. Also, add up the starting watts to the sum of the running watts. Multiply your total wattage by 1.5 to 2 to get an estimate. This is the total watt that will run on your generator. 
  • Choose a 10-20% larger generator for your house than you need for extra available watts.

For calculation, you’ll find the starting and running wattage for home appliances in their manual. Follow the formula below to convert ampere equipment to watts. 

  • Common resistive loads: Watts = amp x volts.
  • For reactive loads: Watts = amp x volts x load factor. 

Remember, when choosing a house generator choosing the best house generator is important. 

What Size Generator Do I Need For A 1,500 Square Foot House?

There are many generator types and models, so you must choose the right generator for your home based on the power requirement. 

Generator TypeSize
Standby 7 – 15 kW
Inverter 7 kW
Solar 1- 5.1 kW (Not Recommended)
Portable 7 – 12 kW

As generators come in different sizes, a 1500-sq ft house with various appliance factors will vary regarding wattage requirements.  

Standby Generators for A 1,500 Square Foot House:

You will require a standby generator to provide you with 7 to 15 kW power for your 1500 sq ft house. These generators are best for a power outage with backup options. 

A 1500 sq ft house with 2-5 ton AC requires a 12 – 17 kW size generator at least. A standby generator is ideal for this requirement. But, the standby generators and their maintenance are costly because they run on gas.  

Inverter Generators for A 1,500 Square Foot House:

Inverter generators are quite sufficient for your 1500 sqft house with minimal appliances as they offer a 2 to 7 kW power rating. These generators can power your essential home appliances and also these come with portability features. 

However, if you are worrying about, the time a generator can run the whole house? That also varies as it depends on the home appliances you’ll use. 

Inverter generators are fuel efficient and come in smaller and lighter sizes. Also, these are quiet and need less maintenance than standby generators. However, they’ll increase your electricity bill and they offer less power output.  

Portable Generators for A 1,500 Square Foot House:

Apart from standby generators, portable generators are most efficient for a 1500 sq ft house. If you have chosen a portable generator then its size must be in the range of 7-12 kW. That is sufficient for a 1500 sq ft house with increased appliances including 2 to 4-ton AC. 

Also, to their portability feature, they are easily installed anywhere. These are also cost-friendly as they will take $20 to $70 per day based on the operation time and size. 

Solar Generators for A 1,500 Square Foot House:

It’s better not to use a solar generator for your 1500 sq. ft house. These offer 1 to 5.1 kW of power output which is only sufficient if you run the essential home appliances only. But for heavy-duty use and larger power requirements, solar generators are not a good choice.  

Note that solar generators are cost-friendly as they do not need gas and run on sunlight. Also, you’ll have much cleaner energy from solar generators for essential appliances. 

Why It’s Important to Get the Right Size Generator for 1,500 Square Foot House

A right-size generator for your 1500 sqft house can save you any extra trouble during power outages or in time for backup. A house that runs on electric power will require more kilowatts than a home that runs on gas. 

So, you’ll need to calculate all of the power requirements for your home including appliances to choose the right generator. While standby generators can give you more power than you need, portable ones will offer you minimum electricity cost. 


So, calculate all the appliances and estimated power requirements to know what size generator do I need for a 1500 square foot house. Choosing the right generator will be beneficial for your house as you can also minimize the electricity cost. Good luck.

Frequently Asked Questions (FAQs):

Can I Run My Whole House on A 12000-Watt Generator?

Yes, you can run your whole house on a 12000-watt generator as it has sufficient power to power all of your required appliances. You can run refrigerators, 3 to 5 lights, AC, dishwasher, microwave, computers, heater, etc on this generator. 

What Will A 3.5 KVA Generator Run?

A 3.5 KVA generator has the capacity to run heavy-duty home appliances such as televisions, refrigerators, electric furnaces, microwaves, etc.

How Long Can A 3.5 KVA Generator Run?

A 3.5 KVA generator can run up to 9 hours at 50% load and up to 6 hours at 100% load. Its 15-liter fuel tank with long-range power output can power a small house with much efficiency. 

Leave a Reply

Your email address will not be published. Required fields are marked *