Ratliff was offered a full scholarship at the University of Wyoming. Entering college, he was 6'7" (200.7 cm) tall and weighed only 160 pounds (72.6 kg). That's much smaller than most of the players he had to guard on a day-to-day basis. In his first year, he was regularly matched up against future Western Athletic Conference (WAC) player of the year Reggie Slater. Slater weighed almost a full 100 pounds more than Ratliff. As Ratliff describes it, "That's like me going up against Shaq at the time."
Although he felt undersized at first, he was never comfortable with the idea of bulking up quickly. He was convinced that once his body had fully developed, he would not need to add on extra weight for its own sake. Instead of trying to become something that he wasn't, he exploited the size difference. In the course of his college career, he found a way to guard much bigger players by taking advantage of his superior quickness and agility. By the end of his time at Wyoming, Ratliff was named the second-best shot blocker in NCAA history and WAC defensive player of the year. Ratliff explains:
I've always been able to play against bigger guys, because I can use my quickness, and I can try to learn the game of how to make guys get off balance, and take advantage of that situation. And therefore be able to block their shots or put them in an awkward situation where they have to check me.
By the time he was chosen by the Detroit Pistons in the first round of the 1995 NBA draft, Ratliff had grown to 6'10" (208.3 cm) and weighed about 225 pounds (102 kg). That's about average for an NBA player in general, but smaller than many of the centers in the league.