Computing Profession

Computers Were Originally Humans

Herbert Bruderer

As a rule, the English term “computer” and the equivalent German term “Rechner” describe calculating machines. But until the middle of the 2oth century, computers were, in fact, humans who performed calculations. This is shown in older specialized books and numerous printed reference works. For complex calculations, the assistance of reckoning centers was required. In calculation halls, human computers worked with mechanical desk calculating machines. This was often the work of women.

Until the 1950s, in the English-speaking countries, computers were humans and not machines. One spoke of human computers and female computers, of a “human computer with a desk calculator.” This was the term for the first female programmers who worked with the monstrous Eniac. The title of a book by David Alan Grier makes this clear: “When Computers Were Human” (Princeton University Press, Princeton 2005). To distinguish them from human computers, the terms digital computer and electronic digital computer were widely used. In these days, the spelling computor (with o) was also occasionally found.

Fig. 1: The Eniac.
This photo (from around 1946) shows two woman programmers in front of the giant computer.
Credit: U.S. Army

Expressions such as calculator (English), calculateur, calculatrice (French), calcolatore, calcolatrice (Italian), and calculador(a) (Spanish) were originally reserved for calculating persons. Later came the terms ordinateur (French), elaboratore (Italian), and ordenador/computador(a) (Spanish), which generally referred to electronic computers. A (German-speaking) “Rechnerin” is always a person. On the other hand, “calculatrice” and “calcolatrice” describe both humans and machines. Other French names are machine à calculer (calculating machine) and calculette (pocket calculator). Other than in English with the words “computer,” “calculator,” and “reckoner,” in German – apart from compound names – only the term “Rechner” is common.

The two quotations below underscore this:

  • “The labour which is involved in computing astronomical data of this kind is very great, and for many years was undertaken by highly skilled computers, most of them elderly Cornish clergymen, who lived on seven-figure logarithms, did all their work by hand, and were only too apt to make mistakes.”
  • “Today no logarithms are needed. About one-third of the staff are astronomers, and the rest computers, many of them young girls who can successfully operate their desk calculating machines but who may be quite unable to explain the complicated functions which they are computing. The complete mechanization of these computations cannot be long delayed.” (see Bertram Vivian Bowden: A brief history of Computation, in: Bertram Vivian Bowden (editor): Faster Than Thought: Symposium on Digital Computing Machines, Pitman Publishing, London 1953, reprinted 1971, page 25).

The following article also touches on this subject: Mary Croarken: Human computers in eighteenth- and nineteenth-century Britain, in: Eleanor Robson; Jacqueline Stedall (editors): The Oxford Handbook of the History of Mathematics, Oxford University Press, Oxford 2009, pages 375–403.

The original meaning of the English term “computer” can be seen from the following entries in British and U.S. reference works:

a person who did computations
The New Encyclopaedia Britannica, volume 16, Encyclopaedia Britannica, Inc., Chicago, London, 15th edition 2007, page 630

computer, also computor
one who computes; a calculator, reckoner; specifically a person employed to make calculations in an observatory, in surveying, etc.
The Oxford English Dictionary, volume 3, Clarendon Press, Oxford, 1989, page 640

computer, also computor
a person who makes calculations; specifically a person employed for this in an observatory, etc. (age of the word: 1630–1669)
The New Shorter Oxford English Dictionary on Historical Principles, Clarendon Press, Oxford 1993, volume 1, page 464

a person who computes or makes calculations
The Concise Oxford English Dictionary of Current English, Clarenden Press, Oxford, 9th edition 1995, page 274, as well as the Oxford English Reference Dictionary, Oxford University Press, Oxford, 2nd revised edition 2003, page 298

a person who makes calculations, especially with a calculating machine
The New Oxford Dictionary of English, Clarenden Press, Oxford 1998, page 379

computer, also computor
one that computes, a person who calculates (as latitudes, longitudes, and areas) for map making from notes provided by engineering survey parties
Webster’s Third New International Dictionary of the English Language, volume 1, G. Bell & sons, Ltd., London/G. & C. Merriam Co., Springfield, Massachusetts 1961, page 468

a person who computes
Webster’s New Dictionary and Roget’s Thesaurus, Thomas Nelson publishers, Nashville, Tennessee 1984, page 149

a person who computes or calculates
Collins English Dictionary 21st Century Edition, Harper Collins publishers, Glasgow, 4th edition 2000, page 330

any device or person that computes
Collier’s Dictionary, volume 1, Macmillan Publishing Company, New York 1986, pages 206 f.

a person who computes
The Chambers Dictionary, Chambers Harrap Publishers Ltd., London, 12th edition 2011, page 323

one who or that which computes
Funk & Wagnalls New international Dictionary of the English Language, comprehensive edition, Library Guild Word Publishers, New York 1987, volume 1, page 269

a person who computes; computist (1640–1650)
The Random House Dictionary of the English Language, Random House Inc., New York, 2nd edition 1987, page 421

somebody who computes; a person who calculates figures or amounts using a machine
Encarta World English Dictionary, Bloomsbury Publishing Plc. London 1999, page 391

Oxford English Dictionary (online)
Definition of computer

  • an electronic device which is capable of receiving information (data) in a particular form and of performing a sequence of operations in accordance with a predetermined but variable set of procedural instructions (program) to produce a result in the form of information or signals,
  • a person who makes calculations, especially with a calculating machine.

Encyclopaedia Britannica (online)
computer, device for processing, storing, and displaying information.
Computer once meant a person who did computations, but now the term almost universally refers to automated electronic machinery.



Bruderer, Herbert: Milestones in Analog and Digital Computing, Springer Nature Switzerland AG, Cham, 3rd edition 2020, 2 volumes, 2113 pages, 715 illustrations, 151 tables, translated from the German by John McMinn,


Herbert Bruderer is a retired lecturer in didactics of computer science at ETH Zurich. More recently, he has been an historian of technology., herbert.bruderer@bluewin.

Join the Discussion (0)

Become a Member or Sign In to Post a Comment

The Latest from CACM

Shape the Future of Computing

ACM encourages its members to take a direct hand in shaping the future of the association. There are more ways than ever to get involved.

Get Involved

Communications of the ACM (CACM) is now a fully Open Access publication.

By opening CACM to the world, we hope to increase engagement among the broader computer science community and encourage non-members to discover the rich resources ACM has to offer.

Learn More