Von Kempelen studied law and philosophy in Pressburg, and attended the Academy in Győr, Vienna and Rome, but mathematics and physics also interested him.
He married twice, first in 1757 to Maria Franziska Piani, who died suddenly in 1758 of an abdominal obstruction, and again in 1762 to Maria Anna von Gobelius, who had served as a lady's companion in the house of Count Johannes Erdödy, the vice-president of the Hungarian Court Chancery.