Performance Measures to Consider

Once you have determined the type of air compressor you would like to buy, you should also consider the level of performance you will need from your new compressor.  Understanding basic measurements of air compressor performance will help you when you are selecting a unit to buy.

  • Pounds per Square Inch (PSI): This is the measure of air pressure delivered by your compressor. The higher the PSI, the further the air can be compressed - meaning a larger volume of compressed air can be stored in the tank.
  • Cubic Feet per Minute (CFM): Volume of air that your compressor can pump in one minute of a specific working pressure. High CFM ratings mean a compressor can provide more air – making higher CFM units more practical for larger applications.
  • Horsepower (HP): This is the unit of measurement for the power your compressor’s electric motor or gas-powered engine produces. Higher horsepower motors or engines produce greater PSI and are capable of carrying a heavier workload.
  • Tank Size: Units with more powerful engines and larger tanks (measured in gallons) can generate higher levels of PSI for longer amounts of working time, providing greater power to your air tools.
  • Formula for Meeting Requirements for Your Tools: The highest volume cubic feet per minute (CFM) at the highest pounds per square inch (PSI) that your tool requires. Then add 50% to the required CFM as a safety margin. For example, if a tool requires 3 CFM at 90 PSI, choose a compressor that provides at a minimum 4.5 CFM at 90 PSI.