Frequently Asked Questions

The Journal Impact Factor (JIF) is a metric that measures the yearly average number of citations received by articles published in a journal during the previous two years. It is calculated by dividing the number of citations in the current year to articles published in the previous two years by the total number of articles published in those two years. For example, if a journal's 2025 Impact Factor is 5.0, it means articles published in 2023-2024 received an average of 5 citations each in 2025.

Impact Factors are calculated annually by Clarivate Analytics as part of the Journal Citation Reports (JCR). The formula is: IF = (Citations in current year to articles from previous 2 years) ÷ (Number of articles published in previous 2 years). For instance, to calculate the 2025 Impact Factor: count all citations received in 2025 that reference articles published in 2023 and 2024, then divide by the total number of citable articles published in 2023 and 2024.

A 'good' Impact Factor varies significantly by academic field. In life sciences and medicine, an IF of 10+ is considered excellent, 5-10 is very good, and 3-5 is good. In physical sciences and engineering, an IF of 5+ is excellent, 3-5 is very good. In mathematics and computer science, an IF above 3 is excellent. In social sciences and humanities, an IF above 4 is considered excellent. Rather than focusing on raw numbers, researchers should compare Impact Factors within their specific field and consider JCR quartiles.

JCR Quartiles divide journals within each subject category into four groups based on their Impact Factors. Q1 (top 25%): These are the highest-ranked journals in the field. Q2 (25-50%): Above-average journals. Q3 (50-75%): Average journals in the field. Q4 (bottom 25%): Lower-ranked journals. Publishing in Q1 journals is often required for academic promotions, tenure decisions, and grant applications at many institutions worldwide.

CAS (Chinese Academy of Sciences) Block classification is a journal ranking system particularly important in Chinese academic institutions. Journals are classified into four blocks: B1 (top tier, most prestigious), B2 (high quality), B3 (good quality), and B4 (standard quality). This classification considers not only Impact Factor but also journal reputation, review process quality, and historical significance in the field.

The 5-Year Impact Factor is calculated similarly to the regular 2-year Impact Factor, but uses a 5-year citation window instead of 2 years. This metric is particularly useful for: fields with longer citation cycles (humanities, social sciences), journals that publish foundational or methodological papers, and assessing long-term influence rather than immediate impact. It provides a more stable measure of journal influence over time.

Journal Impact Factors are updated annually by Clarivate Analytics. The new Impact Factors are typically released in June each year. For example, the 2025 Impact Factors (reflecting citations in 2024 to articles from 2022-2023) were released in June 2024. Our database is updated immediately when new Impact Factors are released to ensure researchers have access to the latest data.

Impact Factors vary between fields due to different citation practices and publication cultures. Some fields (like biomedical sciences) have more researchers, faster publication cycles, and higher citation rates. Other fields (like mathematics) have fewer researchers, longer review times, and papers remain relevant for decades with slower citation accumulation. This is why comparing Impact Factors across different disciplines is not meaningful—always compare within the same field.

Not necessarily. While high Impact Factor journals offer prestige, consider these factors: 1) Journal scope and audience match with your research, 2) Review time and publication speed, 3) Open access options and fees, 4) Acceptance rates and rejection history, 5) Whether the journal reaches your target readership. A well-matched mid-tier journal may provide better visibility for your specific research than a prestigious but poorly-matched high-IF journal.

Impact Factor (Clarivate/Web of Science) uses a 2-year citation window and counts citations from indexed journals only. CiteScore (Scopus/Elsevier) uses a 4-year citation window and includes more source types. Both measure citation impact but use different databases and methodologies. Some journals have significantly different rankings in each system. Many institutions accept both metrics, so check your institution's specific requirements.

You can find journal Impact Factors in several ways: 1) Use our free search tool on this website—simply type the journal name and get instant results with Impact Factor, JCR quartile, and CAS classification. 2) Check the official Journal Citation Reports (JCR) from Clarivate (subscription required). 3) Visit the journal's official website—most journals display their Impact Factor. 4) Check Scopus for CiteScore metrics.

A journal without an Impact Factor may be: 1) Newly launched and not yet indexed (takes 2-3 years to receive first IF), 2) Not indexed in Web of Science (but may be indexed in Scopus or other databases), 3) Focused on a niche field with limited indexing, 4) A predatory or low-quality journal (be cautious). Always verify journal legitimacy through other means: publisher reputation, editorial board, peer review process, and indexing in other databases.

Generally, yes. Higher Impact Factor journals typically have: lower acceptance rates (often below 10% for top journals), more rigorous peer review, longer review times, and more rounds of revision. However, they also offer greater visibility, more citations, and enhanced reputation. Balance your publication strategy with realistic expectations and consider backup journal options.

Journal self-citation occurs when articles in a journal cite other articles from the same journal. While some self-citation is natural (journals often cover specific topics), excessive self-citation can artificially inflate Impact Factors. Clarivate monitors this and may suppress journals with suspicious self-citation patterns. The 'Impact Factor without self-cites' metric is available in JCR for more accurate comparison.

Our search results show: 1) Impact Factor 2025: The latest annual Impact Factor, 2) 5-Year IF: Long-term citation impact, 3) JCR Quartile (Q1-Q4): Ranking within subject category, 4) CAS Block (B1-B4): Chinese Academy of Sciences classification, 5) ISSN: Unique journal identifier. Use these metrics together—a Q1 ranking in your field often matters more than the raw Impact Factor number when choosing where to publish.