Unfortunately, Boban Marjanovic hasn’t had his hands officially measured. In 2016, he compared hands with his former teammate Ray McCallum whose hand size has been officially measured. We can thus use this to estimate his true size. At 6’3", McCallum has pretty small hands for his height. His hand length is only eight inches and his span is 8.75 inches. From the pic, it was pretty obvious that Boban’s hand length was at most three inches longer than McCallum’s. Their hand spans also didn’t differ by more than 3.5 inches. Boban’s hand length is therefore likely to be in the range of 10.75 to 11 inches. His hand span is likely in the range of 12-12.25 inches. You can find the pic of them comparing hands in the link below.