He was educated at Oundle School and Jesus College, Cambridge.
In 1929/30, he was Captain of Jesus College Boat Club, and he rowed in the winning Cambridge crews of the Boat Race in 1930 and 1931 races. Carpmael married Anne Wise, widow of Jock Wise. Prior to her death in 2003 she established a Charitable Trust to preserve the house and riverside land as Withymead nature reserve.