Skip to Main Content
It looks like you're using Internet Explorer 11 or older. This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge. If you continue with this browser, you may see unexpected results.

Research Impact and Citation Analysis: Journal Impact Metrics

Measures & Definitions

  • Impact Factor (JIF)In any given year, the impact factor of a journal is the average number of citations received per paper published in that journal during the two preceding years. The impact factor is based on two figures:  the number of citations to a given journal over the previous two years (A) and the number of research articles and review articles published by that journal over the same two-year period (B), so:  A/B = Impact Factor  (JCR). A 5 year JIF has been introduced more recently.


  • Cited Half-Life - The citing half-life is the median age of articles cited by the journal in the JCR year.
  • Immediacy Index - The average number of times an article is cited in the year it is published.  (JCR)


  • IPP - The Impact per Publication measures the ratio of citations per article published in the journal. (Scopus) More


  • Eigenfactor score - The number of times articles from a journal published in the past five years have been cited in a JCR year.


  • SNIP - Source-Normalized Impact per Paper (SNIP) measures contextual citation impact by weighting citations based on the total number of citations in a subject field.  (Scopus)  More


  • SJR - SCImago Journal Rank (SJR indicator) is a measure of scientific influence of scholarly journals that accounts for both the number of citations received by a journal and the importance or prestige of the journals where such citations come from.  (Scopus)  More

Journal Search

Many journals offer alerting services.  Use Ulrich's to identify journals of interest and to connect to their websites.

Journal Citation Reports (JCR)

Incites Journal Citation Reports analyzes journal citation patterns to determine total cites, journal impact factor, impact factor without self cites, 5 year impact factor, immediacy index, citable items, cited half-life, citing half-life, Eigenfactor Score, and Article Incluence Score for  journals in the sciences and the social sciences. Click Customized Indicators to choose specific indicators to view.

Search by Individual Journal Title:

  1. Search journal title or ISSN in the Go To Journal Profile search box. All indicators and years available will display. See source data options at bottom left.  Includes graphic of journal relationships.

Search by Subject Category:

  1. On the left panel, choose Edition: SCIE (Science Citation Index Expanded), SSCI (Social Science Citation Index), or both. This choice will determine what subject categories display..
  2. Click Select Categories and choose one or more categories.
  3. Select JCR year (1997-2016)
  4. Choose Category Schema: Web of Science
  5. Click Submit at bottom left.
  6. Initial display data includes total cites, journal impact factor, and Eigenfactor Score.  Choose Customized Indicators to select other indicators.

To see category in which a specific journal or journals is contained:

  1. Click Select Journals. Enter journal title, ISSN, abbreviated journal title, or title word.
  2. Choose the JCR year.
  3. Select Science Citation Index Expanded (SCIE) or Social Science Citation Index (SSCI)


Scopus   - Provides these metrics: SNIP (Source-Normalised Impact per Paper), SJR (SCImago Journal Rank), and IPP (Impact per Publication) click on Browse Sources, search for a journal, click on the journal name in the search results. Select a journal to display journal details.  The number of annual articles available will also display. To analyze and compare journals, choose the Compare Sources.  You can compare up to ten journals. 

Journal Metrics from Elsevier (Scopus) - Journal metrics calculated using Scopus data. Covers the 22K journals, as well as books, trade journals, and conference proceedings. Citescore looks at documents from a three year period and the citations received by those documents in the next year.  The three year document total is then divided by the cited by count to get the CiteScore. Covers 2011-2016. Data available by subject categories. Video

SCImago Journal and Country Rank -  is a free Web site that uses Scopus data to calculate SCImago Journal Rank (SJR) and Source Normalized Impact per Paper (SNIP). The metrics compare to Web of Knowledge’s Impact Factor.

Google Metrics

Google Metrics - Scholar Metrics currently cover articles published between 2012 and 2016, both inclusive. The metrics are based on citations from all articles that were indexed in Google Scholar in June 2017. This also includes citations from articles that are not themselves covered by Scholar Metrics.

Eigenfactor and Article Influence

Search for Eigenfactor and Article Influence scoresThe Eigenfactor score is based on five years of data and is calculated by taking the number of times articles from the journal published in the past few years have been cited in the Journal Citation Report year . Scores are scaled so the sum of all journal scores is 100. 

The journal citation data for the Eigenfactor website come from Clarivate Analytics  Journal Citation Reports (JCR). To be included on the Eigenfactor website, a journal either must be listed in the JCR or be cited in the last 5 years by a journal that is listed in the JCR. FAQ and Methodology