I have hand quilted for years and have always counted the stitches on the front. I found this answer on Ask.com. How are stitches per inch counted? About half of the quilters I know count only the ones that show on top. The other half count both top and bottom and divide by two. Which way is right? We haven't decided yet. Forget what you've heard about having to have 15 stitches to the inch, though. That's a fantasy of people with too much time on their hands. A beginner can expect to get 5-7 stitches per inch, and an experienced or professional quilter can do about 12 after years of practice. Most of us are in the 9-10 range.
Hope this helps.