Hinkle received his B.S. in Biochemistry in 1962 from Harvard University. He revived his doctorate in 1967 from New York University, where he worked with Efraim Racker. He joined the faculty of the Section of Biochemistry, Molecular and Cell Biology, in the Department of Biological Sciences at Cornell University in 1968 as an Assistant Professor. Hinkle became a full professor at Cornell in 1983 and served as chair of what was then known as the Department of Biochemistry, Molecular and Cell Biology from 1985 to 1988. He retired in 2014. His work focused on chemiosmotic theory.