I think I remember reading somewhere its 30% front waste that's the entrails head and skin. After that the avg iirc is 50% of the remaining so at 100# you get 70# then 35# from that on avg. If you consider the lost shoulder your probably closer to that number plus how far down the neck or legs you go makes a huge difference. I keep all the meat ribs get smoked the rest is roasts or ground. I don't have a super powered grinder got the Harbor freight one sharpen the blade it shreds everything. Shank gets ground.