Our museum is temporarily closed to support the effort to contain the spread of COVID-19. Read a message from our director, and check our website and social media for updates.

Curta Type I Calculating Machine

Curta Type I Calculating Machine

<< >>
Usage conditions apply
This compact cylindrical handheld calculating machine has black metal sides and a plastic top and operating handle. Eight slots along the side of the cylinder hold levers that are pulled down to set numbers. The digit entered appears at the top of the slot. Holes around the edge of the top reveal the digits of the multiplier, which may be up to six digits large. The result also shows through holes around the edge of the top, and may be 11 digits large. The top may be rotated, as one one would move a carriage on an earlier stepped drum calculating machine. Sliding decimal markers indicate decimal places in entries, multipliers, and results.
To zero the machine, one raises the carriage and rotates a black disc under the operating lever through one turn. The operating handle is pulled out for subtraction and division. A lever on the side of the cylinder may be set for subtraction rather than addition in the revolution counting register.
The machine fits in black metal cylindrical case. The lid of the case turns clockwise to open.
A mark on the side reads: CURTA. A mark on the base reads: System Curt Herzstark (/) Made in Liechtenstein (/) by Contina AG Mauren (/) Type I No 61644. A mark on the lid reads: OPEN.
The Curta calculating machine was invented by the Austrian Curt Hertzstark (1902–1988). Hertstark, a Jew, was subject to imprisonment by the Nazis when they captured Austria. He worked on the design of the Curta during World War II as a prisoner at the concentration camp of Buchenwald, and produced the machine after the war in Liechtenstein. The Curta Type I was sold from at least 1949 until early 1972, when handheld electronic calculators replaced it.
For related documentation, see 1981.0922.02,1981.0922.03 and 1981.0922.04.
Compare to MA.333848. This machine has red marks to make it easier to find the setting levers.
Curt Hertstark, Interview with Erwin Tomash, September 10 and 11, 1987, Oral History 140, Charles Babbage Institute, Minneapolis, Minnesota. Hertstark dates the beginning of production of the Curta to 1949.
Cliff Stoll, “The Curious History of the First Pocket Calculator,” Scientific American, (January 2004), pp. 82–89. Stoll and others give 1947 as the date of introduction of the Curta.
Currently not on view
Object Name
calculating machine
date made
ca 1965
Contina AG Mauren
place made
Physical Description
metal (overall material)
plastic (overall material)
overall: 12 cm x 5.7 cm x 5.7 cm; 4 23/32 in x 2 1/4 in x 2 1/4 in
ID Number
catalog number
accession number
maker number
Credit Line
Gift of John White
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Calculating Machines
Data Source
National Museum of American History
Nominate this object for photography.   

Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.

If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.


Add a comment about this object