# How To Calculate The Right CFM or Airflow For Air Compressors

CFM is the short form of Cubic Feet per Minute (cu ft/min) and as is evident, it has a volume and a time dimension to it. CFM is, in fact, a measurement of how fast air flows into or out of space. The higher the CFM, the higher is the pressure exerted by the tightly compressed air on a pneumatic tool.

Analogous to power, CFM reflects the compressor’s ability to perform work over a certain period of time. While there is no doubt that CFM is a very useful metric of your compressor’s performance, there is, however, a need to understand the concept and arrive at accurate calculations.

Let us first try to understand the relationship between CFM and PSI (Pounds per Square Inch). While the two may seem conceptually alike, they have fairly distinct implications. CFM is the rate of flow of compressed air through a given space. It has a time dimension and is, therefore, a more dynamic metric. On the other hand, PSI is more static and is basically a measure of the pressure created by the compressed air per unit area. CFM is the driver behind PSI, which in turn reflects the Force that a compressor can exert and the amount of work it can get done. Both CFM and PSI determine whether an air compressor can meet your workload demands as each piece of equipment has its own airflow requirement.

There are a number of websites and online calculators that offer a simple and quick calculation of CFM. All you need to do is to enter the variables and within a split second, you arrive at your CFM. However, to gain a deep conceptual understanding of CFM, it is always advisable to do some good old math and arrive at the results through a formula. So, here we go:

CFM = Tank Volume in Cubic Feet x Standard Pressure (ATM) during a Cycle x Cranks per Minute

How to calculate Standard Pressure and Cranks per Minute?

Standard pressure must always be converted to PSI. Remember, 1 ATM = 14.7 PSI

Let’s say, your tank volume is 18 Cu. Ft, Standard pressure is 2 PSI and Cranks per Minute is 1.5.

By simple multiplication of the above-given variables, we get:

18 x 2 x 1.5 = 54 CFM

Another very easy method of calculating CFM is the airflow meter. This gives us the pressure coming out of a fitting and can be installed on individual pieces of equipment or complete systems to provide an instant reading.

For assistance to decide on the air compressor that suits your needs the best, feel free to contact us on +919819907445. We would be happy to assist you in finding the best match based on your requirements. As one of the leading Elgi air compressor dealers and distributors, VEMC provides seamless services to its clients. VEMC is ISO 9001:2015 certified and is a pioneer in the field of electromechanical engineering products, allied equipment, and services.