Financial fallout from sexual-abuse allegations against former U.S. national gymnastics team doctor Larry Nassar will likely soar well past half a billion dollars for Michigan State University, estimates from legal experts indicate, more than twice the cost of the abuse scandal at Pennsylvania State University.

The tally includes possible settlements with about 250 victims, legal fees associated with an army of law firms representing the university and fines. Victim settlements alone could account for over $300 million, based...