A Journal Impact Factor (IF) measures the average citation frequency of a journal's articles within a particular year. The calculation is based on a two-year period, where a journal's citations are divided by the number of total published citable articles. This indicator originated to assist librarians in making journal subscription decisions, and is now frequently used in research communities as a proxy for individual article impact. The strength of association between article and journal impact has been called into question in the literature.
The IF can be found using the tool Journal Citation Reports by Clarivate.