How to calculate the output of an air compressor, in CFM.?
Step 1Determine the volume of your air compressor tank in gallons. This should be clearly marked on the tank itself by the manufacturer. Step 2Divide the tank volume by 7.48 (7.48 equals the number of gallons in one cubic foot.) The number that you get after the division is the tank volume expressed in cubic feet. Step 3Release the air from your compressor. Step 4Begin refilling the compressor with air. Record the amount of time that it takes to refill the tank while paying close attention to the compressor’s tank gauge. You will need to record the psig (pounds per square inch) at two separate times in the refill process: once at the moment the compressor kicks in and once at the moment the compressor kicks out. Step 5Take the psig indicated on the compressor’s tank gauge when the compressor kicked in and subtract it from the psig indicated when the compressor kicked out. For example, if the compressor kicks in at 75 psig and kicks out at 100 psig then the difference would be 25 psig.
