Your average raccoon weighs 20 to 45 lbs, and are typically 16 to 25 inches long, with an extra 12 to 15 inches for the tail. Females are usually smaller than males. However, raccoons weighing as much as 50 pounds have been recorded. 

Opossums on the other hand are typically about the size of a house cat, weighing in at between 6 and 15 pounds and from 24 to 33 inches long. again, males are typically bigger than females. So your typical raccoon is quite a bit bigger than your typical opossum.