Formula for calculating compressor cfm?

[ls1jay]

I installed a new pump on my old devilbiss compressor and am just curious on how much cfm shes putting out. I went with a laplante pump and with the old pump it used to pump from empty to 122psi in 5:15 seconds and with the new pump it goes from empty to full in 4:23 seconds. I wouldnt mind figuring out cfm at 90 psi also. Thanks alot.

 

[A_Pmech]

Here you go:

http://www.truetex.com/aircompressors.htm

 

[KCarGuy]

Even after you have figured out what your compressor can provide, each hose, run, fitting and regulator can effect the output.
I use this little Handy Dandy Tool to check and see what I can get out of each drop.
Kinda like a V8 engine that puts out 500 HP, but your only getting 395 Rear wheel Horses.