Convert between ergs and other major units of energy.

The unit of work in the centimeter-gram-second absolute system of units, 1 erg being the work done by a force of 1 dyne acting through a distance of 1 centimeter, = 10⁻⁷ joules. Symbol, erg.

A million ergs was sometimes termed a megalerg.

The name was first proposed by a committee of the British Association for the Advancement of Science.¹ It is based on the classical Greek word ergon (εργον), meaning work.

According to the current national standard in the United States², the erg is not to be used. The joule should be used instead. Nevertheless, in the 21st century the erg continued to be used in certain fields (see source note 1).

1. We provide the report here.

2. IEEE/ASTM SI10-02.
American National Standard for Use of the International System of Units (SI): The Modern Metric System.
New York: IEEE, 30 December 2002.

See Section 3.3.3.



Flux (10⁻¹⁸ erg cm⁻² s⁻¹ Å⁻¹)

Legend for vertical axis of figure 1a, in
M. D. Lehnert, N. P. H. Nesvadba, J.-G. Cuby, A. M. Swinbank, S. Morris, B. Clément, C. J. Evans, M. N. Bremer and S. Basa.
Spectroscopic confirmation of a galaxy at redshift z ≈ 8.6.
Nature, vol 467, pages 940-942 (20 October 2010). Letter.


Son emploi n'a pas encore prévalu en pratique, où l'on fait usage de centimètres-grammes, grammètres et kilogrammètres.

It [the erg] has not yet been employed in practice, but gramme-centimètres, grammètres, kilogrammètres, and foot-pounds are used.

Édouard Hospitalier.
Formulaire Pratique de l'Electricien.
Paris: G. Masson, 1883.
Page 32.  Translation (1884) by Gordon Wigan.

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