What Size Air Compressor do I Need For an Impact Wrench?

You might wonder what size air compressor you will need for an impact wrench. Although, air compressors exist in a variety of sizes. The size of the compressor does not always define its ability to power your impact wrench. In this post, we’ll show you how to calculate your impact wrench’s air requirements so you can get the correct air compressor.

What Size of Air Compressor is necessary for an Impact Wrench?

The size of an impact wrench determines the size of the air compressor. For a 12-inch impact wrench, you’ll need a 4-5 CFM @90 PSI air compressor.

For example, a 1′′ drive impact wrench requires 10 CFM @90 PSI, a ½” drive requires 4 CFM @90 PSI, and a ⅜” requires 3 CFM @90 PSI.

Most impact wrenches have a 12″ drive. It simply means that you’ll be getting around 4 to 5 CFM @ 90 PSI.

Other factors, though, will decide the size of the air compressor you’ll want. These factors include the type of project, the power source, available space, impact wrench, and ultimate usage.

The CFM indicates the quantity of air that must pass through the tool per minute to function. As a result, the air compressor’s output must equal the impact wrench’s needed CFM. Finally, the size of the tank, measured in gallons, affects how long the impact wrench can run.

DEWALT Air Compressor for Trim, 200-PSI Max, Quiet Operation (DWFP55130)

Why does one need to choose the right size Air Compressor for Impact Wrench?

Whether you’re a weekend warrior, a DIY mechanic or a mechanic, one of the most critical aspects of your task is having a good tool kit. One should think about investing in high-quality tools or relying on more traditional power tools.

Air compressors of various capacities can be used to meet various project needs. You won’t be able to buy an air compressor for your impact wrench in a store.

When you use high-quality instruments, you get the following advantages:

  • Ability to reduce weight to lessen operating fatigue
  • Having the ability to reduce the risk of electric shock or fire
  • Longer life expectancy
  • More power with less heat

You’ll need a suitable air compressor to function correctly with your impact wrench. Pay attention to the following facts if you want to achieve the right size!

What is the best way to size a compressor?

Firstly, establish the necessary compressor capacity by calculating the quantity of CFM (cubic feet per minute) required in a shop. Start by adding the CFM requirements for all the tools and add another 30% to account for unexpected or unusual compressor utilization.

Which air compressor is the smallest for an impact wrench?

The idea is to have an air compressor with tanks and a pump large enough to provide enough CFM for your impact wrench.

You’ll also need to move your air compressor from time to time, so a portable one is preferable. Portable air compressors have a smaller capacity and are lighter in weight.

To figure out what size air compressor you’ll need, you’ll need to know how much airflow the impact wrench takes to work. When you identify the air tool CFM needs in the handbook or technical specification and meet it, your equipment will perform at its best.

In my opinion, a 6-gallon air compressor with 4 CFM is the bare minimum for impact wrenches. Any lower than that, and you’ll have a hard time using the tool. Keep in mind that this is the smallest size available. I strongly advise you to purchase one with a tank capacity of at least 20 gallons.

CFM Chart: Impact Wrench Air Consumption

Please keep in mind that this is merely a guide. For each model, the tool manufacturer will have exact specifications.

Tool Size

Air Consumption


1/4-inch Impact Wrench


90 PSI

3/8-inch Impact Wrench


90 PSI

1/2-Inch Impact Wrench


90-100 PSI

3/4-inch Impact Wrench



1-inch Impact Wrench

10 -16 CFM


What is an impact wrench?

An impact wrench (also known: air wrench, impactor, impact gun, air gun, windy gun, rattling gun, torque gun) is a socket wrench power tool that stores energy in a rotating mass before rapidly delivering it to the output shaft.

What is the purpose of an Air Compressor?

Compressed air is one of the most useful, adaptable, and readily available sources of energy. Most air tools offer adjustable torque control and variable speed to maximize their versatility, and they last longer than traditional tools.

  • Longer life expectancy
  • Controllable speed and torque
  • There is no danger of an electric or shock fire.
  • Produces less heat
  • High power-to-weight ratio
  • There are no pollutants in unintentional air leaks.

What should I pay attention to while buying an air compressor?

Before you buy a compressor, here’s what you should know:

  • Horsepower(HP)
  • Cubic Feet Per Minute (CFM)
  • Air Pressure (PSI)
  • Tank Dimensions.
  • Is it a one-stage or two-stage
  • Oil or oil-free, Direct drive or Belt drive
  • Duty Cycle
  • Moisture issues.

Are you using the Impact Wrench Continuously?

You must consider if your impact wrenches task requires constant or occasional use of the air compressor.

If you need your impact wrench occasionally, a small compressor will suffice; but, if you need it regularly, the compressor must have the discharge capacity that impact wrenches require.

In a non-assembly line context, an impact wrench is likely to be used for significantly less than half of the time, drawing the full-CFM rating.

How much amount of air pressure is necessary for an Impact Wrench?

Most air impact wrench compressors require a minimum of 90 PSI to function correctly. An air compressor with good shut-off pressure is necessary. When shutting down a compressor at 100 PSI, one of the things to consider is pressure loss in the line.

The air pressure for an impact wrench will depend mainly on the size of the impact wrench you are using. There is no one-size-fits-all guide for all air tools. So let us go over the popular impact wrench sizes instead:

Air compressor for 1/4-Inch Impact Wrench

You don’t need a lot of air pressure to use a 1/4-inch impact wrench. For an impact wrench of this size, an air compressor capable of delivering 1 to 1.5 CFM (cubic feet per minute, the measure of air pressure) will be more than adequate. Of course, additional air pressure is an option, but it isn’t required.

Air compressor for 3/8-inch Impact Wrench

You’ll need a little more pressure for a 3/8-inch impact wrench. You’ll need nearly double the power in this case. So keep an eye out for an air compressor with a 3 to 3.5 CFM power rating. Is it possible to go even lower? Maybe. For example, I could imagine a 2.5 CFM air compressor working out, but it would be pushing it.

If you’re buying an air compressor expressly for your 3/8-inch impact wrench, I strongly advise you to spend the extra money on a 3 or 3.5 CFM air compressor.

Air compressor for 1/2-inch Impact Wrench

If you’re familiar with impact wrenches, you’re probably aware that 1/2-inch impact wrenches are the most frequent. They are also in the middle of the size chart in terms of size. As a result, finding the correct air compressor for this size wrench is critical. When it comes to air pressure, you have many alternatives. For a 1/2-inch impact wrench, anywhere from a 3.5 to a 5 CFM air compressor will suffice. If I were to suggest a precise air pressure, I’d say opt for at least a 4 CFM air compressor to be safe.

On that basis, I recommend a 5-CFM air compressor. It strikes a solid balance between all of the features you’d look for in an air compressor.

Air compressor for 1-inch Impact wrench

Finally, I’d like to explain about 1-inch impact wrenches. These are extremely rare and are visible on building sites. Due to the size of these tools, you’ll need a powerful air compressor to operate them. I recommend looking for an air compressor with a CFM rating of 9 to 10. That will be costly, but if you’re using a 1-inch impact wrench, you’re presumably operating in an environment where an air compressor is frequently required, so it’s a sensible investment.

Pro Tip: Consider a two-stage air compressor if you’re working with frozen or rusty fasteners that demand a lot of torque. A single-stage compressor can deliver up to 125 psi, while a two-stage device can deliver up to 175 psi, capable of removing even the most difficult nuts.


Now you should have a good idea of what size air compressor you’ll need for your impact wrench. The air compressors have a storage tank where they may store the air they need. The amount of air in the tank controls the impact wrench’s performance.

An impact wrench and other pneumatic equipment will run smoothly with the correct air compressor. The size of the air compressor determines the functionality of an Air Impact Wrench. So choose your Air Compressor carefully!