Use a meat thermometer inserted in center of meat until bulb rests in thickest part of lean meat (not touching fat) as double check.
For SMALLER ROASTS in each weight catergory, use HIGHER minutes per pound.
Tips:
Roasts will be easier to carve if allowed to stand, covered with foil, about 15-20 minutes after removing from oven. If roast is to stand, remove from oven when thermometer registers 5 degrees lower than desired doneness.