A unit of information equal to 1000 bytes. As a unit of computer storage, however, the kilobyte is usually equal to 1024 bytes, although this should now be called a kibibyte
Russ Rowlett (Director), How Many? A Dictionary of Units of Measurement, Center for Mathematics and Science Education University of North Carolina, USA 2005. http://www.unc.edu/~rowlett/units/dictA.html, (Unit of Meas and Covr Factors - Amer) {608}