Below, 2oz. of DRY pasta. Not much to it, just 2oz. of pasta, weighed out. Not very impressive, and doesn't amount to a whole lot.
I boiled this in a small saucepan, separate from the big batch boiling for the rest of the family.
Here it is after being thrown into boiling, salted water for a bout 12 minutes.
Not a huge difference visually. Maybe doubled. But less pasta than my kids would eat in a sitting. More importantly, is the weight.
The COOKED pasta comes to 126 grams.
Dry pasta: 2oz (aka 56 grams)
Cooked pasta: 126 grams (aka 4.3 ounces)
So, a simple calculation would be that you can measure out 4 ounces of cooked pasta to equal the 2oz. serving size of dry pasta.
When eying it up in my bowl, I figured it was about the size of a Lean Cuisine or other pre-packaged foods for fatties. It's a normal serving size. I ate it, with a little bit of sauce, some olive oil and parmesan cheese, contemplating the me a year ago who would probably eat double that amount. Most restaurants give double or triple that for their portion sizes.
Hope that's helpful to someone else. It sure helped me.

represents 1 pound gone)