Impact Factor vs CiteScore vs SJR
Impact Factor, CiteScore and SJR are journal-level citation metrics from different providers using different databases and formulas. They are related but not interchangeable, and none measures the quality of an individual article.
Comparison
| Metric | Provider and data | Idea (check current definitions) | Notes |
|---|---|---|---|
| Journal Impact Factor | Clarivate, Web of Science | Citations in a year to items of the previous two years divided by citable items | Selective coverage; widely recognised |
| CiteScore | Elsevier, Scopus | Citations over a multi-year window divided by documents in the same window | Broader coverage; calculated and updated by Elsevier |
| SJR (SCImago Journal Rank) | SCImago, Scopus data | Weighted citations, where citations from more prestigious journals count more | Prestige-weighted, not a simple average |
Providers adjust methods and windows, so read the current documentation before quoting values.
Using them
- Compare journals within the same subject area and the same metric.
- Look at quartile rank within a category when available, which allows comparison within a field.
- Remember that coverage differs: a journal may have one metric but not another.
- Combine metrics with qualitative assessment: aims, peer-review process, editorial board, indexing.
Illustrative example
Invented for teaching. A journal appears in Scopus with a CiteScore but is not in Web of Science, so it has no Impact Factor. That does not mean that it is poor; it indicates different indexing. A student checks the journal's quartile in Scopus and its inclusion in PubMed before deciding.
Which one should you quote?
Quote the metric the journal itself reports and name its provider and year, for example "2025 CiteScore, Scopus". If you are advising a colleague, give the quartile rank within the subject category in addition to the number. Avoid ranking journals on a single measure, and avoid using any of these numbers to judge an individual researcher, which is exactly the use that research-assessment declarations caution against.
Common pitfalls
- Comparing numbers from different metrics.
- Trusting "impact factor" claims from websites with no Clarivate listing.
Key takeaways
- Each metric uses its own data and method.
- Use quartiles and qualitative checks, not single numbers.
References and further reading
- Garfield E. The history and meaning of the journal impact factor. JAMA. 2006;295(1):90-93. doi:10.1001/jama.295.1.90
- San Francisco Declaration on Research Assessment (DORA). Link
Related reading
This page is general educational information about research methods. It is not medical, legal or regulatory advice; follow your institution's ethics board and your target journal's instructions.