What Size Generator for Construction Site? Top Suggestions

If you want to know What Size Generator for Construction Site Do you Need? Read this article to see our recommendations, tips, and valuable data.

As a generator and construction site expert, one of the most common questions I receive is “What size generator do I need for my construction site?”

It’s an important question because the right generator size can ensure that your construction site has the necessary power to operate all its tools and equipment efficiently.

The wrong size, on the other hand, can lead to downtime, delays, and even damage to your equipment.

In this article, I will share my expertise on how to choose the right generator size for your construction site, based on the power requirements of your equipment and the specific needs of your project.

What Size Generator For Construction Site Do I Need?

Small portable generators, typically ranging from 1,000 to 6,500 watts, are suitable for smaller construction sites with fewer power needs, such as DIY projects. Large standby generators, which range from 10,000 to 125,000 watts, are more appropriate for larger construction sites with heavier power demands. Standby generators, which range from 12,000 to over 20,000 watts, are a good option for permanent construction.

Factors to Be Considered for Generator for Construction Site

1. Power Requirement 

It’s essential to know the power capacity of each tool and equipment that will be used at the construction site.

This information can be found in the user manuals of the tools and appliances.

Wattage and amperage are the two measurements used to describe the power needs of the equipment.

Totaling the wattage and amperage of all equipment will give an idea of the generator’s power capacity needed to run all the tools efficiently.

2. Construction Project Type

The type of work being done, and the environmental factors can have a significant impact on the choice of generator size.

For instance, a temporary construction site that operates for a short period of time may require a smaller generator, while a permanent construction site that requires a continuous and reliable power supply may require a larger generator.

Additionally, the type of work being done may require specialized equipment that requires more power, such as heavy-duty machinery or power tools.

3. Location of the Construction Site:

It’s important to consider the location of the construction site, including any local regulations or noise restrictions that may impact the type or size of the generator that can be used.

Noise restrictions may require the use of quieter inverter generators, which could impact the generator’s size and capacity. Similarly, local regulations may require the use of specific types of generators or fuel types.

4. Type of Generator:

Different types of generators, such as small portable, large towable, and standby generators, have varying power capacities and are suitable for different types of construction sites.

Small portable generators are suitable for smaller construction sites with fewer power needs, while large towable generators are more appropriate for larger construction sites with heavier power demands.

Standby generators are a good option for permanent construction sites that require a continuous and reliable power supply.

5. Fuel type:

The fuel type, such as diesel or gasoline, can also impact the size and type of generator that is suitable for the construction site.

Diesel generators tend to be more fuel-efficient and have a longer lifespan, making them more suitable for larger construction sites with heavy power demands.

Gasoline generators are more commonly used for smaller construction sites or for temporary power needs. Choose a generator that is fuel-efficient and cost-effective based on the specific needs of the construction site.

Recommended Read: What Size Generator do i need to Run a Welder?

Low Backup Portable Generators (1000 to 5500W)

A generator with a power output of 1,000 to 5,500 watts is suitable for minimal backup power requirements at a construction site.

This size of generator is typically small and portable and can be easily transported around the site to provide power for smaller equipment and tools.

Here are some examples and calculations.

Example 1:

Suppose you are working on a DIY construction project in your backyard and require a generator to power some basic tools and equipment.

A portable generator with a power output of 1,000 to 2,000 watts may be enough.

For instance, a generator with a power output of 1,500 watts can provide enough power for a circular saw (1,200 watts), a drill (400 watts), and a light (100 watts) simultaneously.

Example 2:

Suppose you are managing a small construction site that requires some backup power in case of an outage.

A portable generator with a power output of 3,000 to 5,500 watts may be suitable for your needs.

For instance, a generator with a power output of 4,000 watts can provide enough power for a miter saw (1,800 watts), a table saw (1,500 watts), and a compressor (1,000 watts) simultaneously.

Calculations:

To determine the generator size required for a construction site, you need to add up the wattage of all the equipment and tools that will be in use simultaneously.

For example.

Suppose you need to power a circular saw (1,200 watts), a drill (400 watts), and a light (100 watts) simultaneously for your DIY construction project.

The total wattage required would be:

1,200 watts + 400 watts + 100 watts = 1,700 watts.

This means that a portable generator with a power output of at least 1,700 watts would be suitable for your needs.

Similarly, suppose you need to power a miter saw (1,800 watts), a table saw (1,500 watts), and a compressor (1,000 watts) simultaneously at your small construction site.

The total wattage required would be:

1,800 watts + 1,500 watts + 1,000 watts = 4,300 watts.

This means that a portable generator with a power output of at least 4,300 watts would be suitable for your needs.

Semi-Pro Generators (6000 to 10,000W)

A generator with a power output of 6,000 to 10,000 watts is suitable for larger backup power requirements at a construction site.

This size of generator is ideal for mid-sized construction sites, where a larger number of tools and equipment require power. It can also provide backup power for homes and small businesses during power outages.

Here is an Example and Calculation

Example:

Suppose you are managing a mid-sized construction site with a higher number of power tools and equipment and require backup power in case of an outage.

A portable generator with a power output of 8,000 to 10,000 watts may be suitable for your needs.

For instance, a generator with a power output of 8,000 watts can provide enough power for a circular saw (1,200 watts), a table saw (1,500 watts), a compressor (1,000 watts), and a pump (1,000 watts) simultaneously.

Calculation:

To determine the generator size required for a mid-sized construction site or household, you need to add up the wattage of all the equipment and appliances that will be in use simultaneously.

For example, suppose you need to power a circular saw (1,200 watts), a table saw (1,500 watts), a compressor (1,000 watts), and a pump (1,000 watts) simultaneously for your mid-sized construction site.

The total wattage required would be:

1,200 watts + 1,500 watts + 1,000 watts + 1,000 watts= 4,700 watts.

This means that a portable generator with a power output of at least 4700 watts would be suitable for your needs.

Heavy-Duty Backup Generators (12,000 to 20,000W)

A generator with a power output of 12,000 to 20,000 watts is considered a heavy-duty generator, suitable for powering large construction sites or serving as a backup power source for a large household or business.

These generators are capable of powering multiple large pieces of equipment simultaneously, including heavy-duty power tools, air compressors, and welding equipment.

Here is an example and calculation

Example:

Suppose you are managing a large construction site or a commercial operation that requires significant backup power.

In that case, you may require a generator with a power output of 15,000 to 20,000 watts.

For example, a generator with a power output of 15,000 watts can power multiple large tools, such as a welding machine (8,500 watts) and an air compressor (1,500 watts) simultaneously.

Calculation:

To determine the generator size required for a large construction site or a commercial operation, you need to add up the wattage of all the equipment and appliances that will be in use simultaneously.

For example, suppose you need to power a welding machine (8,500 watts) and an air compressor (1,500 watts) simultaneously for your large construction site.

The total wattage required would be:

8,500 watts + 1,500 watts= 10,000 watts.

This means that a portable generator with a power output of at least 10,000 watts would be suitable for your needs.

However, to account for any additional equipment or appliances that may require power,

I will recommend selecting a generator with a higher wattage, such as 15,000 to 20,000 watts, to ensure enough backup power.

Recommended Guide: What Size Generator Do I Need For My House?

Commonly Used Tools and Appliances on a Work Site

Appliance/Tool	Estimated Wattage
Circular saw	1,400 – 2,200
Concrete mixer	1,000 – 2,500
Air compressor	1,500 – 5,000
Welder (MIG)	60 – 180 Amps
Welder (TIG)	150 – 200 Amps
Grinder	2,000 – 2,500
Hammer drill	1,000 – 1,200
Electric drill	250 – 1,200
Jigsaw	500 – 800
Chop saw	2,000 – 2,500
Heat gun	1,500 – 2,000
Floodlight	300 – 500
Radio	100 – 500

What are the Best Generators for a Construction Site?

Generator Model	Power Output	Fuel Type	Run Time	Noise Level	Portability	Price Range
Honda EU2200i	2,200 watts	Gasoline	3.2 – 8.1 hours	48 – 57 dB(A)	Portable	$1,000 – $1,200
Generac GP6500	6,500 watts	Gasoline	10 – 12 hours	72 dB(A)	Portable	$900 – $1,100
Westinghouse WGen9500	9,500 watts	Gasoline	12 – 17.5 hours	73 dB(A)	Portable	$1,200 – $1,500
CAT RP7500E	7,500 watts	Gasoline	11 hours	74 dB(A)	Portable	$1,000 – $1,200
Briggs & Stratton 30664	8,000 watts	Gasoline	9 hours	78 dB(A)	Portable	$900 – $1,000
Duromax XP12000EH	12,000 watts	Dual Fuel	8.83 hours (gasoline)	74 dB(A)	Portable	$1,200 – $1,500
WEN DF1100T	11,000 watts	Dual Fuel	8.5 hours (gasoline)	78 dB(A)	Portable	$900 – $1,000
Generac XC8000E	8,000 watts	Diesel	32.4 hours	70 dB(A)	Towable	$3,000 – $3,500
Cummins RS20A	20,000 watts	Liquid Propane	10.3 hours	65 dB(A)	Towable	$6,000 – $7,000
Kohler 30RCL	30,000 watts	Liquid Propane	11 hours	64 dB(A)	Towable	$13,000 – $14,000

Frequently Asked Questions (FAQs)