On average, a boneless pork shoulder weighs 4 to 5 pounds. If you're using a bone-in pork butt, it will likely weigh an average of 6 to 8 pounds. For a 4 to 5-pound boneless cut, expect a cooking time of 7 to 8 hours on Low heat, or 4 to 5 hours on High. Bone-in pork butt can take up to two hours longer to cook.