Last Updated on June 25, 2026 by Dr. Bhagat
JOURNAL METRICS·Updated June 2026
What is Journal Impact Factor? Complete guide covering the history, formula, importance, and limitations of JIF. Learn how Clarivate calculates IF for 12,000+ journals and why it matters for researchers, institutions, and funding decisions.
The Journal Impact Factor (JIF) is a metric used to evaluate the relative importance of a journal within its field. First introduced in the 1960s by Eugene Garfield, founder of the Institute for Scientific Information (ISI), it remains one of the most referenced indicators of journal quality in academic publishing today.
GUIDE · Updated June 2026What Is Journal Impact Factor?
Impact Factor (IF) — also called Journal Impact Factor (JIF) — is an index provided by Clarivate Analytics. It measures the frequency with which the average article in a journal has been cited in a particular year.
It is calculated by dividing the number of citations received by the number of articles published in a journal in the two preceding years. For example, a 2025 Impact Factor reflects citations in 2025 to articles published in 2023 and 2024.
UPDATE (June 2026): The new JCR Impact Factor 2025 data has been released! Check out the full list and analysis at JCR Impact Factor 2025.
CALCULATIONHow Impact Factor Is Calculated
The calculation is straightforward in principle:
| Input | Example Value |
|---|---|
| Total Citations in 2024–2025 to articles published in 2022–2023 | 850 |
| Total Articles published in 2022–2023 | 200 |
| Impact Factor (2026 JCR data) | 4.25 |
Impact Factor = 850 ÷ 200 = 4.25
TOOLSMajor Tools to Measure Journal Impact Factor
Several databases provide journal-level metrics. Here are the most widely used:
1. Journal Citation Reports (JCR)
Provided by Clarivate Analytics, JCR is the authoritative source for the Journal Impact Factor. It tracks journals in the sciences and social sciences indexed in the Web of Science Core Collection. JCR provides:
- 2-year and 5-year Impact Factors
- Immediacy Index (citations in the publication year)
- JCR Quartile rankings (Q1–Q4)
- Category rankings
2. Scopus / CiteScore
Developed by Elsevier, Scopus provides the CiteScore metric, which uses a 4-year citation window. Scopus also provides the h-index, SNIP (Source Normalized Impact per Paper), and SJR (SCImago Journal Rank).
3. SCImago Journal & Country Rank (SJR)
A free portal using Scopus data to calculate the SJR metric, which weights citations by the prestige of the citing journal. Available at scimagojr.com.
4. Google Scholar Metrics
Provides h5-index and h5-median rankings for journals and conferences based on Google Scholar citation data. Updated annually.
5. Eigenfactor
Developed by the University of Washington, Eigenfactor measures the total influence of a journal by weighting citations and excluding self-citations. Available at eigenfactor.org.
| Tool | Primary Metric | Database | Access |
|---|---|---|---|
| JCR (Clarivate) | Impact Factor (2-yr) | Web of Science | Subscription |
| Scopus | CiteScore | Scopus | Subscription |
| SCImago | SJR | Scopus | Free |
| Google Scholar | h5-index | Google Scholar | Free |
| Eigenfactor | Eigenfactor Score | Web of Science | Free |
LIMITATIONSWhat Impact Factor Does (and Doesn’t) Tell You
While widely used, the Impact Factor has important limitations:
- It’s an average: A high IF doesn’t guarantee every article is high quality.
- Field bias: Biomedical journals tend to have higher IFs than mathematics or engineering journals.
- Review articles inflate IF: Journals publishing many review articles tend to have higher IFs because reviews are cited more frequently.
- Self-citation: Some journals inflate their IF through excessive self-citation.
- No measure of article-level quality: An excellent paper in a low-IF journal can be more impactful than a mediocre paper in a high-IF journal.
TAKEAWAYSKey Takeaways
Key Takeaways
- Journal Impact Factor measures average citations per article over a 2-year window.
- JCR (Clarivate) is the primary source for Impact Factor data.
- Alternative metrics include CiteScore (Scopus), SJR, SNIP, and h5-index.
- Compare IF only within the same subject category — cross-field comparisons are misleading.
- Use IF as one of several factors when choosing a journal for submission.
FAQFrequently Asked Questions
What is a Journal Impact Factor?
Journal Impact Factor (JIF) is a metric that measures the average number of citations received by articles published in a journal over a 2-year period. It is calculated annually by Clarivate Analytics.
Who calculates the Impact Factor?
Clarivate Analytics calculates the Journal Impact Factor as part of the Journal Citation Reports (JCR), released each June. Scopus provides CiteScore as an alternative metric.
What is a good Impact Factor?
Context matters. In life sciences, 5+ is strong; in social sciences, 2+ is solid; in mathematics, 1.5+ can be competitive. Always compare within the same JCR subject category.
Is Impact Factor the only metric that matters?
No. Researchers should also consider CiteScore, SJR, SNIP, h-index, and journal reputation in their specific field. Article-level metrics (downloads, social mentions) are also valuable.
How often is Impact Factor updated?
JCR Impact Factors are updated annually and released in June each year. The June 2026 release covers the 2025 data year.
Do open access journals have Impact Factors?
Yes. Many open access journals indexed in Web of Science have Impact Factors. Examples include PLOS ONE, Nature Communications, and Scientific Reports.
