Eastman is a former 1000 point collegiate scorer between Geneseo, Middlebury and Brandeis. He played his first two years in 2016-18 with Geneseo, averaging 10.6 points per game. In his sophomore season, he was named to the All SUNYAC Second Team, as he averaged 14.5 points and 9.7 rebounds per game. 
 
He transferred to Middlebury in the 2019-20 season, where he averaged 13.6 points per game and 6.7 rebounds per game, and was named to the All NESCAC Second Team. After COVID canceled the 2020-21 season, Eastman transferred and did a post grad year at Brandeis. 
 
In his only season with Brandeis, Eastman averaged 15.8 points per game and 7.2 rebounds per game. In that season, he was named to the All UAA Second Team, Second Team All Region, and was All Academic UAA.