The joule (/ˈl/ or whiles /ˈl/), seembol J, is a derived unit o energy, wirk, or amoont o heat in the Internaitional Seestem o Units.[1] It is equal tae the energy expendit (or wirk duin) in applyin a force o ane newton throu a distance o ane metre (1 newton metre or N·m), or in passin an electric current o ane ampere throu a resistance o ane ohm for ane seicont. It is named efter the Inglis pheesicist James Prescott Joule (1818–1889).[2][3][4]

Unit seestemSI derived unit
Unit oEnergy
Named efterJames Prescott Joule
Unit conversions
1 J in ...... is equal tae ...
   SI base units   1 kg·m2/s2
   CGS units   1×107 erg
   kilowatt hours   2.78×10−7 kW⋅h
   kilocalories   2.39×10−4 kcal
   BTUs   9.48×10−4 BTU
   electronvolts   6.24×1018 eV


  1. International Bureau of Weights and Measures (2006), The International System of Units (SI) (PDF) (8th ed.), p. 120, ISBN 92-822-2213-6
  2. American Heritage Dictionary of the English Language Archived 2012-06-18 at the Wayback Machine, Online Edition (2009). Houghton Mifflin Co., hosted by Yahoo! Education Archived 2010-11-06 at the Wayback Machine.
  3. The American Heritage Dictionary, Second College Edition (1985). Boston: Houghton Mifflin Co., p. 691.
  4. McGraw-Hill Dictionary of Physics, Fifth Edition (1997). McGraw-Hill, Inc., p. 224.