How long is the line? If it's 25 feet, you'll get about 30 cfm, if it's 300 feet, you'll get around 5 cfm.
For ballparking stuff like this, get a copy of "Handyman In Your Pocket". It has (among MANY other bits of info) a table for compressed air through 1/2" through 1-1/2" sch 40 steel pipe at 100 PSI.
This book is like a "Leatherman" tool. You'll find the people who initially scoff at it are invariably the same ones who repeatedly ask if they can borrow it.
