Few numbers carry as much weight in academic publishing — and generate as much confusion — as the journal impact factor. Authors are routinely advised to “publish in high-impact journals,” yet many never learn exactly what the number measures, where it comes from, or how much it should actually influence their choice of journal. This guide breaks it down plainly.
What Impact Factor Actually Measures
Impact factor is a measure of how frequently, on average, articles published in a journal over the previous two years were cited during the current year. It is calculated by dividing the number of citations a journal received in a given year for articles published in the two preceding years, by the total number of citable articles published in those same two years. In simple terms: it’s an average citation rate, not a measure of quality, rigor, or importance of any individual paper.
Where Impact Factor Comes From
The most widely recognized impact factor is published annually by Clarivate through the Journal Citation Reports, based on citation data from the Web of Science database. Other indexing bodies, such as Scopus, calculate comparable but distinct metrics (like CiteScore), which can produce different rankings for the same journal.
Why Impact Factor Is Not the Full Picture
Impact factor has well-documented limitations that every author should understand before using it as a primary decision criterion:
It’s a Journal-Level Metric, Not an Article-Level One
A high journal impact factor does not mean every article in that journal is highly cited. Citation distributions within journals are typically skewed — a small number of highly cited papers can inflate the average for an entire journal, while most individual articles receive far fewer citations than the impact factor suggests.
It Varies Dramatically by Field
Fields with large, fast-moving research communities (like oncology or immunology) naturally generate more citations than smaller or slower-moving subfields. Comparing impact factors across disciplines is close to meaningless.
It Can Be Gamed
Practices like excessive self-citation, “citation cartels,” and publishing large numbers of review articles (which tend to be cited more than original research) can artificially inflate a journal’s impact factor without reflecting genuine research quality.
It Ignores Newer, Legitimate Journals
Impact factor requires several years of indexed citation history to calculate. Strong, legitimately peer-reviewed journals that are newer or serve smaller specialized communities may not yet have an assigned impact factor — that absence alone doesn’t indicate poor quality.
What Should Actually Guide Your Journal Choice
Rather than relying on impact factor alone, consider:
- Scope fit: Does the journal genuinely publish research in your specific area? Reviewers and readers who understand your subfield are more valuable than a marginally higher number.
- Peer review rigor: Is there a clearly described, credible review process — ideally double-blind, with realistic (not implausibly fast or slow) turnaround times?
- Indexing: Is the journal indexed in recognized databases like Google Scholar, Scopus, or Web of Science, ensuring your work is discoverable?
- DOI registration: Does the journal register articles with a recognized DOI agency such as Crossref, ensuring permanent citability?
- Editorial transparency: Are publication charges, review timelines, and editorial board credentials publicly disclosed, rather than only shared privately on request?
IJMS, for example, is indexed across Google Scholar, Scopus, and Web of Science, uses double-blind peer review with a defined 3–5 day turnaround, and registers every accepted paper with a DOI through Crossref — the kind of concrete, verifiable markers that matter more for most researchers than a single composite metric.
The Bottom Line
Impact factor is a useful data point, not a verdict on quality. A rigorously reviewed, well-indexed journal with a smaller impact factor but a strong fit for your research area will often serve your work — and your career — better than chasing a marginally higher number in a mismatched journal.
Final Thoughts
When choosing where to submit your next manuscript, weigh scope fit, review rigor, and indexing alongside — not instead of — citation metrics. Review the IJMS Scope and start your submission through the Paper Submission page.
For an authoritative technical explanation of how impact factor is calculated, see Clarivate’s Journal Citation Reports documentation.