I agree with marubozo. The 50% loss number is a good standard to use. We find that both pork butts and packer briskets lose between 40% to 50% from cooking. It all depends on the quality/leanness of the product. We calculate a 50% loss just to be safe. We calculate our loss on every cook and have found that it has been holding steady at 45% loss. We use the same supplier each time so the product quality is uniform. That extra 5% gives us a little buffer in finished quantity.
Do I smell SMOKE?????