Informational Guide

What Size Air Compressor Do I Need For An Impact Wrench?

Our guide will teach you what size is ideal for your impact wrench, so you can equip your garage better.

If you are working on cars, the an air impact wrench is an essential tool to have nearby. But you might be asking, what size air compressor do I need for an impact wrench? With our guide, you will know what air compressor for an impact wrench is ideal so that you can equip your garage.  

As you investigate what size air compressor to run an impact wrench, you might wonder why you should bother with this power tool to begin with. However, there are a few reasons to use an air-powered impact wrench to complete your automotive jobs.  

  • Longer Life Span  
    Because the air impact wrench has a simpler design than many other wrenches, it is considered a more durable option. On top of that, the air impact wrench is simple to maintain and repair, thereby lowering your overall costs.  
  • Variable Speed And Torque Control  
    You can find air impact wrenches with variable speeds and plenty of torque control. However, the air impact wrench doesn’t offer as much of this as some other impact wrenches, especially if you aren’t using the right compressor.  
  • No Risk Of Electric Shock And Fire Hazard  
    Because of the air-powered design, you are running a safer wrench. Unlike some of the other options, the air wrench isn’t going to put you at risk for a fire or electric shock. It’s the safer option to use overall.  
  • Generates Lower Heat  
    With constant air flow circulating through the impact gun, there is less heat generated by rotating parts. You can use it across long hours without worrying about the possibility of overheating, making it ideal for a busy automotive repair shop.  
  • High Ratio Of Power  
    You will be able to get maximum power out of the air impact wrench. Plus, the amount of power you receive doesn’t cost a lot to achieve, especially if you already have a compatible air compressor in the shop. If you are working on tough jobs, you will want this additional power.  
Old Air Compressor

What Size Air Compressor Do I Need For An Impact Wrench?  

Do you know how big of an air compressor to run an impact wrench? The most important consideration is the size impact wrench you plan to use. By looking at some of the most common impact wrenches, we can help you answer – what size air compressor do I need for an impact gun.  

1/4- Inch Impact Wrench 

Your 1/4-inch impact wrench doesn’t require a ton of pressure. With an air compressor that produces 1 to 1.5 CFM, you should have more than enough for this size wrench. Of course, if you have a larger air compressor, it won’t hurt anything.  

3/8- Inch Impact Wrench 

A little more power is needed with a 3/8-inch wrench, probably around double. Look for an air compressor that has a rating of 3 to 3.5 CFM. You might be able to go a little lower, but you don’t want to cut corners.  

1/2- Inch Impact Wrench 

The most common wrench type is the 1/2-inch. Most auto mechanics are going to have this wrench on hand but will also need the right compressor to pair with it. Ideally, you want to choose a 4 to 5 CFM air compressor to get the job done.   

1 Inch Impact Wrench 

Not everyone is going to work with 1-inch impact wrenches, but if you do, you need a high-powered air compressor. Pick an industrial compressor that produces 9 to 10 CFM. While these are going to be costly, you don’t want to sacrifice power when you are doing heavy-duty jobs.  

Impact Wrench Size 

Air Consumption Per CFM (Cubic Feet Per Minute) 

Air Pressure (PSI) 


1.5 CFM 



3 CFM 



5 CFM 



10 CFM 


Impact Wrench With Tire

Other Factors When Choosing An Air Compressor 

Type & Size Of Project 

Before you can determine what size compressor for an impact wrench, you need to determine what you are using the power tool for. If you are only planning to purchase a small impact wrench for the occasional job, you can get away with a smaller air compressor.  

Tank Size & Shape  

If you purchase a large air compressor, you will need the space to put it. The more air the compressor holds and outputs, the larger of a space you will need. If you are keeping it in your home, having a large air compressor might not be ideal. Instead, you might prefer looking at getting an air compressor for a home garage 


We’ve already discussed why the CFM is important when deciding the minimum air compressor for an impact wrench. However, the PSI is just as important. By determining what the pound per square inch measurement is, you know exactly what the air compressor is rated for.  

Portability & Ease of movement 

Are you planning to use the air compressor on the go or transport it to various job sites? If so, you need to look through the best portable air compressor options. These can provide the power you need but offer the flexibility to move around when you have a remote job to tackle.  

Impact Wrench Head

People Also Ask (FAQs)

Will a 3-gallon air compressor run an impact wrench? 

The 3-gallon compressor is common in many households, but it’s not designed to run air tools. Most of these compressors contain air pressure of 0.5 CFM, which is far lower than the minimum needed of 1 to 1.5 CFM.  

Can a small air compressor run an impact wrench? 

A small air compressor isn't going to produce the CFM or have the PSI needed to run air tools. Instead, follow our guide above to find the smallest possible air compressor for your size impact wrench.  

Why are air tools better than electric? 

Air tools are the best kind of power tools if you already have an air compressor and want the maximum output. With air tools, you can get the toughest jobs done quickly and efficiently.  


What size air compressor do I need for impact tools? Even with the smaller air impact wrench, you don’t want anything smaller than a 1-1.5 CFM compressor. By choosing the right compressor, you make the toughest jobs easy as pie.