How to Know What PSI is Needed for an Air Compressor

Air compressors produce pounds per square inch, or PSI.

A nail gun can require up to 3 CFM and 100 PSI.A nail gun can require up to 3 CFM and 100 PSI.
The PSI a particular air tool requires is labeled on the packaging. The packaging will also provide the cubic feet per minute (CFM). The PSI and the CFM the air compressor produces must be greater than the tool requires. Some tools require more PSI and CFM than others. An air brush, for example, only needs 1 CFM and 15-50 PSI, while an air hammer can require up to 20 CFM and 70 to 100 PSI.

Choose the air compressor that you will use based on the PSI and CFM that your tool requires. Consult the packaging that came with the tool. Alternatively, if you know your air compressor's PSI and CFM capabilities, you can buy a tool that works within the parameters of the air compressor's output. Check that output in the air compressor's documentation.

Double the tool's CFM if you want to know what rated compressor you will need. For example, if the tool's CFM is 10 at 70 PSI, say for a ¾-inch impact wrench, purchase a compressor rated for 20 CFM.

Quadruple the tool's CFM if you want to know what rated compressor you will need for a tool that runs all the time. For example, if a sander's CFM is 10 at 70 PSI, purchase an air compressor that is rated for 40 CFM.

About the Author

Patrick Nelson has been a professional writer since 1992. He was editor and publisher of the music industry trade publication "Producer Report" and has written for a number of technology blogs. Nelson studied design at Hornsey Art School.