Curta

Curta is a compact hand-cranked mechanical calculator designed by Curt Herzstark. It became one of the best-known portable calculators of the mechanical era, prized for its portability and precision. The name Curta is derived from the designer’s name.

The instrument is housed in a cylindrical case that can be gripped in one hand. A crank at one end is turned to operate the mechanism. Digits are entered with input controls around the curved exterior; the user sets the numbers before turning the crank. The device performs addition, subtraction, multiplication, and division through its gear train, and the results are shown on display wheels at the front with a separate control for the decimal point.

Curt Herzstark, an Austrian engineer, conceived the calculator in the 1930s–1940s. He continued development while imprisoned in a camp during World War II. After the war, production moved to Liechtenstein, and the first Curta calculators were produced in the late 1940s. The model gained popularity with engineers, surveyors, and scientists, offering a compact alternative to larger calculating machines. Production continued into the 1960s as electronic calculators emerged.

Today Curta is celebrated as an icon of mechanical engineering. Surviving examples are highly prized by collectors and historians for their craftsmanship and historical significance.