Q. What is considered a good impact factor?

Impact Factors are used to measure the importance of a journal by calculating the number of times selected articles are cited within the last few years. The higher the impact factor, the more highly ranked the journal. It is one tool you can use to compare journals in a subject category.

In 2024, the Journal Citation Reports (JCR) database tracked impact factors for 21,916 journals. The table shows the number of journals in each impact factor category. Only a tiny fraction - 144 journals (less than 1%) - achieved an impact factor of 20 or above. Expanding to journals with impact factors of 10 or higher was still only about 2.3% of all journals.

Overall, very high impact factors are quite rare, with most journals having impact factors below 2. What one field considers a high impact factor, may not be the same in another field.  Publication patters vary significantly between fields. For example, fields with overall lower impact factors may publish papers that have longer-lasting relevance and will spread citations out over more years. Or fields with a smaller researcher community will have less articles published each year and may have less citations per paper as a result.  In contrast, life sciences and biomedical fields have the highest impact factors due to larger researcher communities, higher publication rates, more co-authorship, and more frequent citations.  The highest cited journals often publish breakthrough research and benefit from high visibility leading to a very high citation count as well as high rejection rates.

While impact factors are useful, but they should not be the only consideration when judging quality. Not all journals are tracked in the JCR database and, as a result, do not have impact factors. New journals must wait until they have a record of citations before even being considered for inclusion. The scientific worth of an individual article has nothing to do with the impact factor of a journal.