Well most people have lager calves than the average trooper. Here are a couple threads and websites that should help:
Thighs:
-----
Also keep in mind the left thigh is larger than the right one. To make them match you will have to cut a wedge that is larger at the bottom of the left thigh. You can use a tailor's tape measure to determine how much to cut, but it is several inches off the bottom and an inch or two off the top.
When cutting use masking tape, or painters tape and mark where you are going to cut. If your using a dremel or razor cut from the inside, that way if you mess up, the mark won't be seen.