What Is CFM Air Compressor? How To Calculate The Right CFM?

If you own an air compressor, you must heard of CFM, and you might be wondering what is CFM air compressor. CFM is an important term used in the world of air compressors. It might sound complex, but it is imperative to know “What is CFM air compressor?” 

You must know this term to keep your air compressor working in optimal condition. It will help you to run the right tools for the right duration. So, if you want to know what CFM means or how to calculate it, you are at the right spot. 

In this guide, we will answer “What is CFM air compressor and how to calculate it?” We will also find the difference between other air compressor terms, such as SCFM and PSI. So, to know everything about the term CFM, you need to stick around us and keep reading!

What Is CFM Air Compressor?

CFM stands for Cubic Feet Per Minute and measures the airflow capacity of your air compressor under actual conditions. In simpler terms, we can say CFM indicates how fast an air compressor fills. 

If you are using air tools like pneumatic drills, nail guns, or spray guns, knowing the CFM rating of your compressor is essential. While operating such tools, you should match the CFM rating of the compressor to the tool requirements to ensure efficient performance. 

For example, if you are using a tool that needs a higher CFM than your compressor range, the tool cannot work correctly. In other words, we can call CFM the breathing power of your air compressor under actual or real conditions. 

How To Calculate the CFM Air Compressor?

To operate your pneumatic tools at the correct CFM rate, you must know how to calculate it. It might sound difficult to calculate the CFM, but it is just like a piece of cake. You can calculate the CFM air compressor like a pro with some knowledge. Here are the simple and quick steps to measure the CFM air compressor; 

  • Check your air compressor tank volume in the gallons. You can find this in the product specification manual. 
  • Divide this volume value by 7.48 to convert the tank’s volume into cubic feet.
  • Now, start releasing air from the compressor.
  • Next, refill the air compressor while timing how long it takes to replenish the tank. 
  • Also, monitor the pressure gauge and note the PSI (pounds per square inch) when the compressor starts and stops. 
  • Label these measurements as PSI 1 and PSI 2.
  • Now, calculate the refill pressure by subtracting PSI 1 from PSI 2. 
  • Then, divide this difference by 14.7 to convert it into atmospheric pressure.
  • Multiply the tank volume (in cubic feet) you measured earlier by the pressure increase in the compressor tank during the refill.
  • Now convert the results into minutes. 
  • Then, multiply the converted value by 60, and you will get the CFM air compressor. 
  • You should double-check the procedure to ensure you follow the correct steps. 

What Is a Good CFM Rating for an Air Compressor?

A good CFM for an air compressor depends on what you want to do with it. Most small, portable home compressors have a CFM rating between 0.5 and 5, which is usually fine for many tasks. If you want to use small rolls like light air guns, a lower CFM rating would be sufficient for you. However, to run heavy pneumatic tools, a high CFM air compressor is essential. 

For example, a compressor with a CFM rating of 5 at 90 PSI is excellent for using small air tools and inflating tires. However, the right CFM for you really depends on the specific air tools you plan to use. To find the right CFM, you should also check your tool requirements. 

If your tool needs a high CFM rate, you should opt for a big tank-size air compressor with more CFM. It can run heavy tools, making your tasks simple and quick. So, in short, a “good” CFM rating is the one that matches job needs. 

Air Tools and their CFM

Different air tools have different CFM requirements. Some need high CFM, while others can work efficiently even at a low CFM rate. Let’s have a look at some air tools and their CFM requirements: 


Air Tools CFM Rate At Particular PSI Level
Angle Grinding5 to 8 CFM @ 90 PSI
Ratcheting2 to 6 CFM (Varies by size) @ 90 PSI
Sawing5 CFM @ 90 PSI
Painting3 to 11.5 CFM @ 90 PSI
Mini Grinding4 to 6 CFM @ 90 PSI
Dual Sanding11 to 13 CFM @ 90 PSI
Frame NailingAround 2.2 CFM @ 90 PSI
Drilling3 to 6 CFM @ 90 PSI
Brad Nailing0.5 CFM @ 90 PSI


What Is the Difference Between CFM and PSI In Air Compressor?

CFM and PSI are two important terms used in air compressors. You may wonder what is the difference between CFM and PSI. If so, we are here to answer your query. 

CFM is the Cubic Feet Per Minute. While PSI is the Pounds Per Square Inch. CFM measures the volume or flow rate of air that an air compressor can deliver. It tells you how much air the compressor can push out in a minute. On the other hand, PSI indicates the pressure or force that an air compressor can produce. 

Knowing the CFM is essential to run the right tools at a suitable CFM rate. The CFM value usually varies based on different tools and air compressor size. While PSI is crucial for ensuring that the compressed air has enough force to operate air tools, inflate tires, or perform other tasks.

What Is the Difference Between CFM and SCFM?

If you own an air compressor, you might be confused about CFM and SCFM. These booths are important terms used in air compressors. Although both measure the volume or airflow rate, they are different. But the question is, “What is the difference between CFM and SCFM?” Let’s find out!

As we have discussed earlier, CFM is the Cubic Feet Per Minute, and it measures the actual volume under the actual circumstances. It means in CFM, the actual conditions, such as temperature, humidity, and pressure, can vary and are not constant. 

At the same time, SCFM is the Standard Cubic Feet Per Minute. It measures the volume or airflow rate at specific or standard conditions. These conditions are humidity, pressure, and temperature. Any fluctuation in these standard values can vary or disturb the SCFM rate. 

However, it is important to note that both CFM and SCFM are essential for the efficient performance of your air compressor. 

How To Increase the CFM of an Air Compressor?

Most people ask if we can increase the CFM of our air compressor. The answer is simple: yes. It is possible to increase the CFM range of an air compressor, which is not a heavy task. There are many simple ways to increase the CFM of your air compressor. 

The first one is to increase the pressure. Some air tools work at high PSI and CFM. If you have less CFM air compressor, you can increase the pressure to run your tool accurately. 

Moreover, you can also use an additional receiver tank. Installing an additional air receiver tank can help increase CFM by storing compressed air. Using this tank, you can also adjust the CFM level depending on your tool requirement. 

Let’s Wrap It Up!

In conclusion, understanding “what is CFM air compressor” is important to ensure the correct working of your air tools. CFM stands for Cubic Feet Per Minute. It measures the volume or airflow rate of the air compressor under actual conditions. 

Unlike SCFM, conditions such as humidity, pressure, and temperature can vary in CFM. To run the right air tools at the right rate without worrying about heating up, you must know the CFM rate. For running heavy tools, a high CFM air compressor is best. While for small and simple tasks, you can also opt for air compressors with a lower CFM rate. We can also say a “good” CFM rating is the one that aligns with your job needs. 


  • What is CFM Air Compressor?

CFM is the Cubic Feet Per Minute, and it measures the volume of your air compressor under actual conditions. It indicates the flow rate of air that an air compressor can deliver

  • Does a Higher CFM Mean a Better Compressor?

A higher CFM does not necessarily mean a better air compressor. In fact, the CFM requirement depends on your job. You would need high CFM air compressors for heavy duties, while a lower CFM rating is enough for small tasks. 

  • Is CFM More Important than PSI?

For the correct working of your air compressor, both CFM and SCFM are equally important. Both these terms are measured together and tell how much pressure and volume your air compressor can deliver.

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