What Is The Difference Between PSI And CFM? » PowerToolsUS

What Is the Difference Between PSI and CFM?

As air compressors have various types of rating it can become quite a bit confusing on what they really mean. Such as what is psi and cfm and what is the difference between psi and cfm?

Without knowing what they mean it can really hurt you if you are buying an air compressor or are just looking to get one.

Or maybe you have just started using your air compressor. 

Difference Between PSI And CFM?

Quick Answer: Generally, the PSI is used to measure pressure and the CFM is used to measure the volume. Both of them together describe the maximum pressure and air volume produced by the air compressors.

Let’s take a detailed look at both of them. 

What Is PSI?

The term PSI means Pounds per Square Inch and In short P = Pressure, S = per Square, I = Inch.

It is the measure of how many pounds of the pressure exerted on a single square inch of space e.g if an air compressor is rated to have 90 PSI that means that 90 pounds of force are to be exerted per square inch.

PSI is usually written in a lower letter (psi) in the specs list of the air compressor and the majority of air tools require between 40 or 90 psi to run efficiently. 

What Is CFM?

The term cfm stands for Cubic Feet per Minute and In short C = Cubic, F = Feet, M = per Minute.

And it is also called SCFM and ACFM.

The SCFM stands for Standard cubic feet per minute and ACFM stands for average cubic feet per minute.

The CFM in air compressors is used to measure how much volume of the air is delivered by the compressor or how much the compressor air can move per minute.

In simple terms how much an air compressor pushes out the air to power the air tools.

If an air compressor has 20 CFM rating then that means 20 cubic feet of air is flowing per minute and a compressor with a higher CFM rating is usually used for industrial applications or for larger jobs as they provide more air. 

Relation Between PSI and CFM

Both of these ratings are important when you are looking for an air compressor to buy as they will affect your work.

As air tools require certain cfm and psi to work so be sure to check it.

Both of these terms characterize the air compressor performance 

What’s the difference between CFM and SCFM?

The units which measure the airflow of a compressor are CFM and SCFM.

The CFM indicates the volume of air that a compressor delivers to an air tool.

So if an air compressor has a higher cfm then they are better for large and heavy jobs.

The SCFM also is the same unit that measures the volume of air the compressor delivers to the air tool but the difference between CFM and SCFM is that the SCFM is measured in a standard pressure, relative humidity, known temperature and it can vary from place to place.

But in CFM it shows how much cubic feet of the compressor air is blowing out in a minute but in this, both the temperature and pressure are variables as there is not standard pressure or temperature set for CFM. 

Which Air Compressor Will Be Best For My Air Tool?

This question may be arising in your mind well how do I choose the best air compressor for my air tools.

Well, as you will have probably understood the difference between PSI and CFM now all you have to do is check the requirements of your air tools.

Check both the PSI and CFM of the air compressor and then compare it with your air tools.

By doing this you will easily get the air compressor according to your needs.

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