During the last years, various useful metrics have been developed for measuring the performance of authors. However, contrary to the popularity of Impact Factor for journals, author metrics are not very popular.

Gaining the popularity of the Journal Impact Factor, we calculate the Impact Factor for authors. However, the number of publications by an author may massively fluctuate from year to year, as opposed to journals, which normally publish the same number of papers each year (or change with a steady rate). Therefore, we calculate the Lifetime Author Impact Factor, which is based on the same principle, but with a slightly different definition of the publication and citation periods.

The lifetime Author Impact Factor is calculated by dividing the number of citations for each article by the number of years from its publication date. The average of these normalised citations makes the LAIF.