After losing 147 pounds, I ended up with about 20 pds of excess skin. I went to see a plastic surgeon and that's what he told me. I used that to create a 'virtual' weight in order to decide when to phase off, when I had reached a healthy BMI.
There is a great post somewhere about the body and skin, but can't remember who posted it. So much depends on your age, genes, how long you were overweight and how much you lost.
I use a homemade skin cream with argan oil, aloe jelly and beeswax cream, to keep the skin moist, if nothing else. Have also been doing strength training like crunches to help with the belly overhang. Too soon to tell if it will help, but something's got to!
My doctor said to give it a couple years and the body has an amazing ability to reabsorb some of that skin, so don't give up.