Tom, I started with almost your exact same dimensions three weeks ago. I measured this morning and I am now at 7.25. I know it is hard to believe, but I’m seeing it with my own eyes. I have been measuring after stretching, which I found out the other day is a no-no, but still, stretched or not, my erect length now is an inch and a half longer than it was three weeks ago. I know this is not true “growth”—it is not physically possible for cells to divide that fast, but I see the difference with my eyes, and my wife can tell the difference, too. Anyway, I know my results are not typical, but now I know that it is possible. I keep expecting my gains to stop, but until they do, I’m going to keep doing what I’ve been doing (stretching as often and for as long as I can).
To get back to your original question, from what I’ve read here, you can expect anything from no gains, to an inch or two. It all depends on your physiology and commitment.
By the way, I’m going to post a picture later to back up my 7.25 claim. Unfortunately I didn’t take a pic before I started, but seriously, if I had a 7.25 inch dick to start off with, I never would have even thought to look for this site. Thundersplace rocks, and Thunderss is DA MAN!