PLOS Biology’s Journal Impact Factor (JIF)

PLOS Biology’s Journal Impact Factor (JIF) is a specific instance of the general Journal Impact Factor metric published annually by Clarivate in the Journal Citation Reports (JCR) — but PLOS itself, as a matter of explicit editorial policy, does not promote or display a current JIF figure for its journals, including its flagship, PLOS Biology. That policy is more useful and more citable for a research-administration audience than any individual tracker’s number, and it is the main correction this page makes to an earlier version that quoted third-party figures as if PLOS endorsed them.

PLOS’s own policy: it does not promote an Impact Factor

PLOS’s journal-information page states directly: “We do not consider Impact Factor to be a reliable or useful metric to assess the performance of individual articles but will provide the metric to individuals when specifically requested.” CASRAI verified this language directly on journals.plos.org’s journal-information page (last verified 16 August 2026); the same boilerplate policy language appears across PLOS’s journal-information pages, including PLOS Biology’s. Rather than headlining a JIF, PLOS’s own metrics pages promote article-level metrics (ALMs), Scopus’s CiteScore and SJR, and the author-level h-index. This position is consistent with the stance of DORA (the San Francisco Declaration on Research Assessment) and the CoARA coalition, both of which discourage using a single journal-level citation ratio as a stand-in for the quality of an individual article or researcher — PLOS is a DORA signatory and its metrics-page language reflects that commitment in practice.

What that means for citing a number

Because PLOS itself declines to headline a JIF, any specific figure in circulation for PLOS Biology is necessarily coming from a third party — most commonly Clarivate’s own Journal Citation Reports (JCR), which does compute and publish a JIF for PLOS Biology as a JCR-indexed title even though PLOS does not foreground that number on its own site. Clarivate’s JCR database itself sits behind institutional-subscription authentication and could not be checked directly by CASRAI. If a specific figure is genuinely needed — for a CV, grant narrative, or tenure file — the reliable path is: (1) check whether your institution has JCR access via a library subscription and look up PLOS Biology directly in jcr.clarivate.com, current cycle the 2025 data year, released June 2026; or (2) per PLOS’s own stated policy above, request the figure directly from PLOS. Do not substitute a number quoted by a third-party JCR-tracking aggregator or Wikipedia’s infobox for either of those — aggregators update on their own schedules and can diverge from Clarivate’s actual current release.

What the JIF measures, mechanically, when it does exist

Where a journal does carry a Clarivate JIF, the figure is a ratio: citations received in a given year to citable items (articles and reviews) the journal published in the two preceding years, divided by the number of those citable items. PLOS Biology launched in 2003 as one of the founding journals of the Public Library of Science (PLOS) and has been JCR-indexed since shortly after launch, publishing peer-reviewed research across the biological sciences.

PLOS Biology vs. PLOS ONE: not the same editorial model

Both journals are published by PLOS and both are JCR-indexed titles, but their editorial models differ in a way that matters for interpreting any figure that does surface. PLOS ONE is a megajournal that peer-reviews submissions for scientific and methodological soundness only — is the work rigorously conducted and reported — and publishes on the order of thousands of articles a year across nearly every discipline, explicitly decoupling acceptance from subjective judgments of novelty or significance. PLOS Biology, by contrast, is a selective flagship title: it reviews for soundness and for perceived significance and broad interest to biologists, accepting a small fraction of submissions and publishing a far smaller, more curated volume than PLOS ONE. That difference in scope and selectivity is a large part of why any reported figures for the two journals diverge, and it means a citation ratio from one PLOS title should not be assumed to describe the other, even though both come from the same publisher, the same stated metrics policy, and the same Clarivate methodology where a JCR entry exists.

Worked example (illustrative, not the journal’s real figures)

Using round, hypothetical numbers rather than PLOS Biology’s actual annual citation and publication counts: if a journal published 1,000 citable items across the two preceding years, and those items received 6,900 citations in the JCR data year, the resulting JIF would be 6,900 / 1,000 = 6.9. This is the same mechanical calculation Clarivate applies to every JCR-indexed title — what varies between journals is the citation and publication volume feeding it, and how selectively those citable items were chosen in the first place, not the arithmetic.

Why this number alone is a poor stand-in for quality

Citation-tracking organizations including DORA, the CoARA coalition, and Clarivate itself caution against over-relying on a single journal-level metric to judge an individual article or researcher. That caution applies to PLOS Biology despite its selectivity, and PLOS’s own stated policy agrees: even a curated flagship journal’s year-level citation average, sourced from wherever it can be found, blends together very different citation trajectories across the articles it publishes, so the figure still says little about any one paper.

Counter-example

PLOS Biology’s CiteScore (a separate Elsevier/Scopus metric using a four-year citation window and a broader document set, and one of the metrics PLOS does actively promote) is not the same figure as its Clarivate JIF, and reporting one as if it were the other is a common sourcing error. Likewise, assuming PLOS Biology’s editorial bar for significance is identical to PLOS ONE’s soundness-only bar because they share a publisher is a common category error — the two journals select differently, and their acceptance rates diverge accordingly.

Keeping this current

Last verified by CASRAI: 16 August 2026, directly against journals.plos.org/plosone/s/journal-information (policy language shared across PLOS’s journal-information pages). This page no longer repeats third-party-tracker or Wikipedia-sourced Impact Factor figures for PLOS Biology, since PLOS’s own stated policy is not to promote one; check jcr.clarivate.com (institutional access required) for a specific number if one is genuinely needed. JCR figures generally refresh each June with Clarivate’s new release, so any figure obtained from JCR directly should be rechecked after that date.

Related terms

• Journal Impact Factor (JIF) — the general metric this page discusses in the specific context of PLOS’s policy toward it.
• PLOS ONE’s Journal Impact Factor (JIF) — the sibling PLOS title, and the direct megajournal-vs-flagship contrast for this page.
• PLOS ONE Author Contributions Statement — PLOS’s shared authorship-disclosure policy, illustrated via its sister title.
• CiteScore — the metric PLOS actively promotes in place of the JIF.
• DORA (San Francisco Declaration on Research Assessment) — the reform commitment behind PLOS’s stated position.
• Impact Factor vs. h-index — a related metrics comparison.
• How to look up a journal’s Impact Factor — practical guide to finding a current, authoritative figure.

Frequently Asked Questions

What is PLOS Biology’s impact factor?

PLOS itself does not promote or display a current JIF for PLOS Biology — its own journal-information page states it does not consider Impact Factor “a reliable or useful metric to assess the performance of individual articles” but will provide it on request. CASRAI verified this policy language directly on journals.plos.org (16 August 2026). For the current 2025-data-year number, check jcr.clarivate.com with institutional access, or request it directly from PLOS, rather than relying on a third-party tracker or Wikipedia.

Why doesn’t PLOS publish PLOS Biology’s Impact Factor directly?

PLOS’s stated policy, confirmed directly on its journal-information page, is that it does not consider Impact Factor a reliable or useful measure of an individual article’s performance, though it will provide the figure on request. PLOS instead promotes article-level metrics, CiteScore, SJR, and the h-index — a position consistent with DORA and CoARA guidance, and one PLOS applies as a DORA signatory.

How is PLOS Biology’s Journal Impact Factor calculated, where one exists?

The JIF is a ratio: citations received in a given year to a journal’s citable items (articles and reviews) from the two preceding years, divided by the number of those citable items. For example, 6,900 citations to 1,000 citable items would produce a JIF of 6.9 — the same formula Clarivate applies to every JCR-indexed title.

Is PLOS Biology’s impact factor the same as its CiteScore?

No. CiteScore is a separate metric calculated by Elsevier/Scopus using a four-year citation window and a broader set of source documents, while the Journal Impact Factor is calculated by Clarivate using a two-year window. PLOS actively promotes CiteScore over the JIF.

Why does PLOS Biology’s reported impact factor differ from PLOS ONE’s?

PLOS Biology is a selective flagship journal that reviews submissions for both technical soundness and perceived significance to biologists, publishing a small, curated fraction of what it receives. PLOS ONE, by contrast, reviews for technical soundness only and publishes a much larger, less selective volume. That difference in editorial selection is a large part of why any reported figures for the two journals diverge.

Should PLOS Biology’s impact factor be used to judge an individual article?

No, and PLOS’s own stated position agrees. DORA, the CoARA coalition, and Clarivate itself caution against using a single journal-level metric like the JIF as a proxy for the quality of a specific paper or the merit of an individual researcher’s work.