What Size Generator Do You Need To Run Power Tools?

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To run smaller power tools like drills, electric chainsaws, and small air compressors individually, a 2200 peak watt generator can be big enough.

For more medium-sized devices like a circular saw or jackhammer, you will need a 3500 watt generator and potentially something bigger to run the power tools separately.

If you want to run bigger power tools like 1 HP air compressors or multiple smaller ones at the same time, a 5500 peak watt generator or something stronger may be needed.

As you can expect, your power needs will depend on the exact power tools you want to run and how many of them.

To play it safe and get the generator size right from the start, it can be smart to find out how many watts your power tool brands actually need.

How big a generator do you need to run power tools?

For smaller power tools like drills, small air compressors, and electric chainsaws, 2200 peak watt generators will often be big enough.

To run more medium-sized power tools like a circular saw and jackhammer you will need a good 3500 watt generator and potentially something bigger depending on your machines.

For bigger power tools like a 1 HP air compressor, you want a generator with at least 5500 peak watts.

Ideally, you would figure out the energy needs of the power tool brands you intend to use. Especially if you want to run multiple of these at the same time.

Energy needs of specific power tools

The rough guidelines on what size generator you need to run power tools can be helpful but you also may have questions about specific tools.

You can find a few of the most popular power tools and rough estimations for their energy needs (plus a margin of safety) right here (1).

Keep in mind that it can be smart to get an inverter generator to make sure you don’t speed up the wear and tear of your power tools or other electronics you run.

What size generator do you need to power a drill?

You generally want a 1000 watt to 1100 watt generator to power a drill although the exact size depends on your exact tool.

For example, a 3/8 inch, 4 amp drill will typically only require 600 peak watts and 440 running watts.

On the other hand, a 1/2 inch hand drill will require more something like 900 peak watts and 600 running watts.

What size generator do you need to run an air compressor?

For example, since a smaller 1/2 HP air compressor often requires around 1600 starting watts, 975 running watts, and a safety margin, you want a generator with about 2000 peak watts.

A 1 HP air compressor will require more in the direction of 4500 starting watts and 1600 continuous watts so you would need a generator size of around 5500 peak watts.

How strong your air compressor is will influence your power needs and generator size a lot.

What size generator do I need to run a circular saw?

You would want a generator of around 3000 peak watts to run a circular saw since a heavy duty, 7.25 inch circular saw requires around 2300 starting watts and 1400 continuous watts.

Any differences in circular saw sizes can also influence power needs.

What size generator do you need to run an electric chainsaw?

To run an electric chainsaw you typically need at least an 1800 peak watt generator since a 14 inches, 2 HP electric chainsaw requires about 1100 watts (both starting and running).

In this case, you don’t just want to look at the peak watts of a generator although this is the main number brands show.

More specifically, 1800 peak watt generators (and bigger sizes) tend to offer more than 1400 running watts which are needed to run an electric chainsaw.

What size generator do you need to run a jackhammer?

To run a jackhammer you need a 3500 watt generator and potentially a bigger size to play it safe.

The watt needs of jackhammers can vary from 1300 starting and running watts to 3000 running watts and potentially more.

Ideally, you would figure out the power needs of your jackhammer before investing in a portable generator for it.

That being said, if you want to play it safe, you would get at least a 3500 watt generator and potentially a bigger size to run a jackhammer.

What size generator do you need to run a 15 amp rotary hammer?

To run a 15 amp rotary hammer you need at least a 2200 watt generator or something stronger.

A 15 amp rotary hammer will often need 1800 running watts or less than that.


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Mats is the founder and head editor of Generator Decision. With a combination of critical thinking, tireless research, and a healthy interest in electronics he helps people find the right generators and how to use these. At this point in the journey, Mats has done research on hundreds of portable generators.