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What Size Air Compressor for Plasma Cutter- In-depth Discussion

Wondering do plasma cutters need air compressors?

The answer is- any plasma cutter requires an adequate force of air pressure to function effectively. Compressed air is the basic requirement for a plasma cutter to work. A superheated starting arc heats the compressed air of the unit to a point where it transforms into plasma. So, any plasma cutter needs an air compressor.

Do all plasma cutters need air compressors?

No, if your plasma cutter doesn’t come with a built-in or internal air compressor, you should invest in an external air compressor.

Now, you may ask yourself, “what size air compressor do I need for plasma cutter?”

Your answer is Here.

Keep continuing reading to learn.

What Size Air Compressor for Plasma Cutter- (Plasma Cutter Air Requirements)

“How big air compressor your plasma cutter needs”- depends on four things:

First, your plasma cutter’s size
Second, the type of materials you cut
Third, the thickness of the workpiece
Fourth, the type of operation

Each unit will have its specific air pressure and airflow requirements. These requirements may differ between models and brands. Each plasma cutter manufacturer indicates the minimum requirements in the owner’s manual.

For example, Hypertherm Powermax45 requires a minimum of 6 CFM at 90 psi.

hypertherm powermax45

Air Pressure:

It refers to how much force of the compressed air is being fed to your machine. It is represented in PSI ( pounds per square inch), megapascal (MPa), or bar.

Air compressor’s inlet pressure comes preset, which is usually between 100 and 135 psi. On the other hand, you can adjust the output pressure by the pressure regulator.

best pressure regulator

A small handheld 20-30 amps plasma cutter may require as little as 80 psi (5.5 bar). Again, a larger unit such as a 130 to 800 amp plasma cutter may require 115 psi (8 bar) or more.

Due to the incorrect air pressure setting, you may lose efficiency and cut quality. It is recommended to set your compressor’s output pressure slightly higher than the inlet pressure requirement of your plasma cutter.

Air Flow

It represents how much air pressure the compressor can deliver per minute. It is referred to as CFM (cubic feet per minute). The standard air flow is expressed as SCFM (standardized cubic feet per minute).

A higher CFM means more air being pumped through your system at any given time,
The flow capacity of an air compressor largely depends on the size of the tank.

A basic plasma cutter may require 4 to 8 CFM (cubic feet per minute) at 90 to 120 PSI (pounds per square inch). Generally, the unit can cut steel 3/8” thick with this configuration.

How many cfm does a plasma cutter need?

If you only use your unit occasionally for hobby projects, you can go for an air compressor with a cfm rating slightly higher than the minimum requirement listed in your owner’s manual.

Air compressor size directly correlates to the metal thickness you want to cut. So, if your projects involve cutting thick metal or doing a lot of cutting, you should use an air compressor that offers flowrate 1.5 to 2 times greater than the minimum requirements of your plasma cutter.


Although air pressure and airflow requirements affect the quality performance of your unit, these are not only the factors that figure into the equation. Beyond choosing the right size air compressor, you need to ensure air quality.

If you use a too small compressor, it may burn out. Poor air quality that contains dust, oil, or moisture results in poor cuts. It may also damage your plasma cutter.

To prevent moisture and dirty air from getting into your system, it is important to use an air drying/filtering system.

air filter

I highly recommend Pneumatic Plus Three Stage Air Drying System to protect your plasma cutter.

three stage air drying system

Air compressor output rating is calibrated to a specific humidity level, temperature and altitude. You may notice that the CFM rating has an “S” in front of it. “S” means the standard cubic feet per minute.

This rating is calibrated to 0% humidity, 68ºF, and sea level. If any of these numbers of these conditions goes up, your compressor output will go down.

So, what to do if you don’t want to spec your plasma cutter air compressor for ambient conditions?

Well, You need to add a 50% fudge factor.

For example, if your unit requires 4 CFM at 100 PSI, get a compressor rated at least 6 CFM.


To sum it up, if you need to use an external air compressor, it needs to be big enough to keep up with your plasma cutter’s air consumption.

best air compressor for plasma cutter

For a 30 amp plasma cutter, Campbell Hausfeld 30 Gallon Vertical Portable Air Compressor (XC302100) can be a good choice.