[1] Born in Milwaukee, Wisconsin, Kranz graduated from Custer High School.

Kranz began playing football for the Milwaukee State Teachers College (currently known as the University of Wisconsin–Milwaukee), but was drafted into military service during World War II.

At the age of 26, he became the first UWM player to be drafted to a professional football team.

The Green Bay Packers selected Kranz in the 21st round of the 1949 NFL draft.

At that time he decided on leaving the team to return to school after discussing it with his wife, Shirley.