Overview of journal impact factor

Journal impact factor (JIF) is one of the most well-known and widely used metrics to evaluate the influence and impact of academic journals. Developed by Eugene Garfield and introduced by the Institute for Scientific Information (ISI), now part of Clarivate Analytics, JIF has become a cornerstone of scholarly assessment. Created in 1969 to help librarians make collection development decisions, journal citation reports (JCR) publish annual results that rank journals in the fields of science, technology, and social sciences. Here is a comprehensive look at what JIF is, how it is calculated, and its significance in academia.

What is JIF?

JIF is a measure that reflects the annual average number of citations received by the most recent article published in a journal. This factor is often used to compare the relative importance of journals within a particular field or discipline. It provides a proxy for the quality and impact of the journal.

How to calculate JIF?

JIF calculation is straightforward, but it only focuses on a narrow quotation window:

For details:

  • The numerator (citations): this is the number of citations in a given year (Year X) to articles published in the previous two years (Years X-1 and X-2).
  • The denominator (published articles): this is the total number of “citable items” (usually articles and reviews) published in the journal during those two years.

For example, the JIF for a journal in 2023 would be calculated based on citations received in 2023 from articles published in 2021 and 2022.  Suppose that in 2021 and 2022 there are 100 articles cited in a journal. In 2023, those 100 articles were cited 400 times. Divide the total citations (400) by the total articles (100) to get the 2023 JIF of 4.0. In other words, articles published in the previous two years received an average of 4 citations during the JCR year.

Why is JIF important?

JIF has several important applications and implications in the academic community. First, JIF is used as an indicator to assess the quality of a journal. A high JIF indicates that the journal has high prestige and influence. Furthermore, JIF influences authors’ decisions on which journals to submit their manuscripts. They tend to choose journals with high JIF to increase the visibility and quality of their work. In addition, JIF is also a metric that universities and research institutes use to measure the quality of research output and evaluate faculty performance and decisions related to tenure. Finally, funding agencies and grant committees also use JIF as a criterion to assess the quality of research proposals and researchers’ track records. Thus, JIF is important in assisting decision-making and quality assessment in academia.


JIF remains a prominent and influential metric for assessing the impact of academic journals. Despite its limitations, JIF continues to play an important role in the scientific publishing ecosystem, guiding researchers and institutions in their decision-making process. Understanding the methodology and context of JIF is essential for its proper use and interpretation in evaluating academic research and publications.

By: I. Busthomi