The capital of Baden, then still a margravedom, is oriented around the castle like a fan. Where exactly Karl Drais was born there is not known. His father Wilhelm baron von Drais, aged 30, was a senior civil servant and Privy Councillor and like all civil servants lived near the castle, presumably on the Zirkel as the street is called till today. His mother, aged 28, was a baroness von Kaltenthal. His first child and only son was born on April 24, 1785 and baptized a Protestant at home the same day. The christening was attended by the ruler Carl-Friedrich who served as godfather and his three sons, of whom the youngest named Ludwig became the employer of the Councillor's son in the forest commission and later still the ruler. Accordingly the Councillor chose the prenames of his son to please the ruling family: Karl Friedrich Christian Ludwig Drais von Sauerbronn.

The Drais family were civil servants without landed property that had to enter a duke's service for a living. The ruler and godfather decided on Karl Drais for the forest service later on, although there was a glut of applicants.

Karl attended secondary modern school in Karlsruhe stressing natural sciences, since he had problems with Latin. The headmaster experimented then with optical telegraphs and pupil Karl Drais will follow in the headmaster's footsteps with binary coding and his stenograph. Yet a stroke of fate occurred: His father overburdened with workload was struck by epileptic seizures.