Journal-level bibliometrics use citations to measure the impact a journal has in the scholarly community. 

Journal-level bibliometrics can be used to help an author decide where to publish and to help librarians decide which journals to subscribe to.

Self-citations and differences in citation patterns across disciplines article types are limitations associated with journal-level bibliometrics. For example, review articles are cited at higher rates than original research articles. Consequently, journals that exclusively publish review articles have much higher journal metrics than journals that publish original research articles.

Scholarly Impact can help create reports and visualizations using bibliometrics to compare journals. Please contact us for assistance.

Journal Impact Factor (JIF) is the most widely used journal-level bibliometric. It is a proprietary metric calculated by Journal Citation Reports (JCR) using citation data indexed in the Web of Science Core Collection.

From JCR: "It [JIF] should be used with careful attention to the many factors that influence citation rates, such as the volume of publication and citations characteristics of the subject area and type of journal. The Journal Impact Factor can complement expert opinion and informed peer review. In the case of academic evaluation for tenure, it is inappropriate to use a journal-level metric as a proxy measure for individual researchers, institutions, or articles."

JIF is defined as all citations to the journal in the current JCR year to items published in the previous two years, divided by the total number of scholarly items (these comprise articles, reviews, and proceedings papers) published in the journal in the previous two years. Though not a strict mathematical average, the Journal Impact Factor provides a functional approximation of the mean citation rate per citable item. A Journal Impact Factor of 2.5 means that, on average, the articles published one or two years ago have been cited two and a half times.