What is the difference between PSI and CFM?

If you’re in the market for an air compressor, then you’ve probably come across the terms “PSI” and “CFM”. But what do these acronyms actually mean? In this article, we’ll explain the difference between PSI and CFM so that you can make an informed decision about which air compressor is right for you.

What is PSI?

PSI is an acronym for pounds per square inch and is a unit of measure for pressure. PSI is often used to measure the pressure of air or water. For example, a tire may be inflated to 30 PSI, meaning that it has 30 pounds of force per square inch of area.

What is CFM?

CFM, or Cubic Feet per Minute, is a measure of airflow. It tells you how much air is moving through space in a minute. CFM is important because it determines how quickly a fan can move air through a room. The higher the CFM, the faster the fan will be able to move air.

Difference Between PSI and CFM

The difference between PSI and CFM can be confusing to understand, but it is important to know so that you can buy the right air compressor. PSI stands for pounds per square inch, while CFM stands for cubic feet per minute. Both are measurements of pressure and airflow respectively.

PSI is a measure of pressure created by a given amount of force applied over an area of one square inch. This unit of measure is commonly used in the automotive, construction, and manufacturing industries when describing pressurized liquids or gases. The higher the PSI, the more pressure there will be on an object or surface being compressed or forced against another object or surface. For example, a swimming pool may have a water pressure reading of 30 psi when full; this means that if the pool were empty, the water would still exert 30 lbs of force across each square inch within the pool’s walls and floor.

CFM, on the other hand, measures airflow over time in cubic feet (ft3). It is most often used in reference to air compressors because it tells us how much air can be compressed into a tank over time – how many cubic feet of air can be placed back into a tank in one minute’s worth of work. Air compressors use CFM as their primary measurement for determining power since it reflects how quickly an air compressor can pressurize and build up energy stored in its tank(s).

Another way to look at the difference between PSI and CFM would be to imagine them as two sides of a coin. The PSI measures the amount of pressure created by pushing air into something like an engine cylinder or tire while CFM measures how much volume (air) is entering that same area over a given period of time. While both measurements are important when selecting an air compressor, they should not be thought of separately; rather they should be seen together as one unit as they both depend on each other to correctly describe an engine’s power output capabilities.

For instance, if we needed to find out how much total power a car’s engine could generate we would need to look at both its PSI rating (how much force per square inch) and its CFM rating (how many cubic feet per minute) since together they determine how powerful your car’s engine will be under various conditions such as temperature or altitude changes.

In summary, understanding the differences between PSI and CFM is essential when selecting an appropriate air compressor for your needs; understanding that they both play off each other in order to accurately define overall power output will help you make informed decisions about what type/size/power level you need from your new compressor before purchasing it. A good rule of thumb when shopping for compressors is that generally larger tanks require more horsepower and higher levels of compression (PSI), whereas smaller tanks require less horsepower and lower levels of compression (CFM).


Now that you know the difference between PSI and CFM, you can decide which one is right for you. If you need a lot of power, then PSI is the way to go. If you need a lot of airflows, then CFM is the way to go.

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