Nephron Extra
- ISSN-L
- 1664-5529
- OpenAlex ID
- S2764705019
- APC list price
- $1,949
2025: no OJR in this release. Latest calculable OJR: 0.82 in 2021. Last eligible ranking: Q3 in Nephrology, 2017.
Nephron Extra has no quartile in OpenJournalRank’s 2025 ranking. OJR quartiles are calculated independently of SCImago, Scopus and JCR quartiles.
OpenAlex-listed APC: US$1,949 (source snapshot September 23, 2026). Check current charges with the journal.
No 2025 values in this release: the cards below show 2021, the latest year with figures.
The OpenJournalRank Indicator (OJR) is a free, publicly available metric of a journal’s field-normalized citation impact, computed from open OpenAlex citation data. It compares citations to a journal’s papers from the previous three years with the world average for papers of the same subfield, year and type, so 1.00 is the world average and values can be compared across fields. It is computed with the NCI3 method. For 2021 it counts non-self citations to the articles, reviews and conference papers a journal published in 2018–2020. Ranks and quartiles order journals by OJR within the subfield, the field and all journals.
0.82
—Not ranked
The Impact factor (2-year) counts citations made in 2021 to the articles, reviews and conference papers a journal published in the two previous years (2019–2020), divided by the number of those papers. Self-citations count; citations from repository-hosted works do not. It is not normalized by field. Clarivate’s Journal Impact Factor™ uses the same basic formula but gives different numbers, and this site does not show it. Clarivate also counts citations to editorials, news and letters while dividing only by articles and reviews. OpenAlex sets document types automatically. The citing data differ: OpenAlex links references for most but not all works, and we leave out repository-hosted citing works. Publication years and snapshot dates also differ. Because of these differences, our value can be higher or lower than the JIF for a given journal, so don’t compare the two directly.
—
No 2021 value
Change not available
Why is it different?
- Journals usually quote Clarivate’s Journal Impact Factor™ (JIF).
- Same idea: citations this year to papers from the past two years, divided by those papers.
- The JIF also counts citations to editorials, news and letters but divides only by research papers. We count citations to research papers only.
- Different citation data (OpenAlex, not Web of Science) and timing.
So the two numbers can differ, in either direction, and the size of the difference has not been established. Compare ours with other journals here, not with the JIF.
Full explanation →Not ranked in 2021: 2 citable documents in 2018–2020, below the 30-document minimum.
Computed by OpenJournalRank from the OpenAlex snapshot of September 23, 2026; 472,521,793 citations counted across this release.
Looking for Clarivate’s Journal Impact Factor™? Check the Master Journal List
OJR rank in each category · 2017
The badge is the quartile; Q1 is the top quarter of ranked journals. Each track runs from the bottom of the category (left) to the top (right), shaded by quartile. The bold marker is this journal and the thin tick the category median. The outlined box is the likely rank range: the 95% interval from re-drawing the journal’s papers 1,000 times. “Spans Q1–Q2” means that range crosses a quartile boundary.
Not ranked in 2025. These are its 2017 ranks, the last year it was eligible.
Ranking categories are derived from OpenAlex paper classifications and may differ from a journal’s stated scope.
At a glance
Quartile history in every category and the key figures for 2021, drawn as small charts.
Quartile by year
Each cell is the journal’s quartile among ranked journals in that category and year, by OJR. Q1 is the top quarter. Years run 2000–2025; tap or hover a cell for the exact rank.
2025Subfield · NephrologyNot ranked
Each track runs from the bottom of the category (left) to the top (right), shaded by quartile. The bold marker is this journal, the outlined box its likely rank range and the thin tick the category median.
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Citations made in 2021 to papers from 2019–2020, divided by the number of those papers, next to the same value a year earlier.
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Everything the journal published in 2021, split into articles, reviews and other items such as editorials. The line shows the last ten years.
0
Citations made in 2021 to papers from 2018–2020, divided by the number of those papers. Includes self-citations. The line shows the last ten years.
2.5
The median number of 2021 citations per paper from 2018–2020, next to the mean (cites per document). A mean far above the median means a few papers draw most of the citations.
2.5
Share of the journal’s 2018–2020 papers that are among the most cited 10% for their subfield, year and type. The marker at 10% is the world baseline.
0.0%
Share of 2021 citations to the journal’s 2018–2020 papers that come from the journal itself. The tick on the ring marks the field median.
0.0%
Share of documents published in 2021 that are free to read, across all document types.
—
Share of documents published in 2021 with authors in two or more countries.
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All-time OpenAlex values at the snapshot date, not limited to the ranking window. The h-index is the largest h such that h papers have at least h citations each; the i10-index counts papers with at least 10 citations.
24h-index
Over the years
Impact factor (2-year)
Show the data as a table
| Year | Impact factor (2-year) |
|---|---|
| 2025 | — |
| 2024 | — |
| 2023 | — |
| 2022 | — |
| 2021 | — |
| 2020 | 2.50 |
| 2019 | 1.40 |
| 2018 | 1.17 |
| 2017 | 1.64 |
| 2016 | 1.30 |
| 2015 | 1.16 |
| 2014 | 1.80 |
| 2013 | 1.26 |
| 2012 | 0.44 |
| 2011 | — |
OJR
Show the data as a table
| Year | OJR | Field median |
|---|---|---|
| 2025 | — | 0.67 |
| 2024 | — | 0.66 |
| 2023 | — | 0.66 |
| 2022 | — | 0.66 |
| 2021 | 0.82 | 0.66 |
| 2020 | 0.79 | 0.72 |
| 2019 | 0.47 | 0.70 |
| 2018 | 0.48 | 0.70 |
| 2017 | 0.65 | 0.72 |
| 2016 | 0.69 | 0.73 |
| 2015 | 0.55 | 0.74 |
| 2014 | 0.65 | 0.75 |
| 2013 | 0.58 | 0.73 |
| 2012 | 0.23 | 0.76 |
| 2011 | — | 0.75 |
Documents by type
Show the data as a table
| Year | Articles | Reviews | Other |
|---|---|---|---|
| 2025 | — | — | — |
| 2024 | — | — | — |
| 2023 | — | — | — |
| 2022 | — | — | — |
| 2021 | 0 | 0 | 0 |
| 2020 | 0 | 0 | 0 |
| 2019 | 0 | 0 | 0 |
| 2018 | 2 | 0 | 0 |
| 2017 | 8 | 0 | 0 |
| 2016 | 3 | 1 | 0 |
| 2015 | 10 | 0 | 1 |
| 2014 | 23 | 0 | 0 |
| 2013 | 15 | 0 | 0 |
| 2012 | 35 | 0 | 0 |
| 2011 | 27 | 0 | 0 |
Citations to the previous three years
Show the data as a table
| Year | From other sources | Self-citations |
|---|---|---|
| 2025 | — | — |
| 2024 | — | — |
| 2023 | — | — |
| 2022 | — | — |
| 2021 | 5 | 0 |
| 2020 | 25 | 0 |
| 2019 | 17 | 0 |
| 2018 | 25 | 0 |
| 2017 | 57 | 0 |
| 2016 | 77 | 0 |
| 2015 | 91 | 0 |
| 2014 | 118 | 0 |
| 2013 | 77 | 1 |
| 2012 | 12 | 0 |
| 2011 | 0 | 0 |
Share in the top 10% of their field
Show the data as a table
| Year | Top 10% share |
|---|---|
| 2025 | — |
| 2024 | — |
| 2023 | — |
| 2022 | — |
| 2021 | 0.0% |
| 2020 | 0.0% |
| 2019 | 0.0% |
| 2018 | 0.0% |
| 2017 | 4.4% |
| 2016 | 5.4% |
| 2015 | 1.4% |
| 2014 | 4.0% |
| 2013 | 3.2% |
| 2012 | 0.0% |
| 2011 | — |
Collaboration and open access
Show the data as a table
| Year | International collaboration | Open access |
|---|---|---|
| 2025 | — | — |
| 2024 | — | — |
| 2023 | — | — |
| 2022 | — | — |
| 2021 | — | — |
| 2020 | — | — |
| 2019 | — | — |
| 2018 | 0.0% | 100.0% |
| 2017 | 25.0% | 100.0% |
| 2016 | 0.0% | 100.0% |
| 2015 | 45.5% | 100.0% |
| 2014 | 17.4% | 100.0% |
| 2013 | 33.3% | 100.0% |
| 2012 | 42.9% | 100.0% |
| 2011 | 44.4% | 100.0% |
Similar journals
Journals ranked nearest to this one in Nephrology by OJR in 2017, the last year this journal was ranked.
- #32Revista de investigaci�n Cl�nicaQ3OJR 0.73
- #33International Journal of NephrologyQ3OJR 0.72
- #34Hemodialysis InternationalQ3OJR 0.71
- #35Clinical NephrologyQ3OJR 0.70
- #36Peritoneal Dialysis InternationalQ3OJR 0.70
- #37Nephron Extra (This journal)Q3OJR 0.65
- #38Journal of NephropathologyQ3OJR 0.65
- #39Therapeutic Apheresis and DialysisQ3OJR 0.64
- #40Kidney International ReportsQ3OJR 0.61
- #41Renal FailureQ3OJR 0.60
- #42Case Reports in Nephrology and DialysisQ3OJR 0.59
Detailed breakdown
The figures behind the charts, written out in full.
The two headline numbers
OJR is OpenJournalRank’s index, computed with the NCI3 method. It divides the non-self citations that papers published in 2018–2020 received in 2021 by the citations expected for papers of the same subfield, publication year and type worldwide. For 2018–2020, papers in this journal received 82% of the citations expected worldwide for comparable papers.
The Impact factor (2-year) is simpler: citations made in 2021 to the papers published in 2019 and 2020, divided by the number of those papers. This journal has no Impact factor (2-year) for 2021. It counts self-citations and is not adjusted for field, so a value of 5 means something different in economics and in molecular biology.
This value is computed from OpenAlex and is not Clarivate’s Journal Impact Factor™. The two use different citation sources and different rules for which items count, so the numbers will not match. Across all core journals, 87.7% of articles and reviews published in 2021 have at least one matched reference in OpenAlex (86.1% in 2020). This is a corpus-wide share: it does not measure how complete any one journal’s reference lists are, and no value on this page is adjusted for it.
How this score was computed
Citations made in 2021 to articles, reviews and conference papers published in 2018–2020. Actual and Expected include only papers with a subfield.
- Actual (non-self citations)
- 5
- Expected (world-average expectation)
- 6.121834
- OJR standard error
- 0.4959
- Most-cited paper's share of citations
- 80.0%
- Citable papers in 2018–2020
- 2
- Classification coverage
- 100.0%
- Share of citable papers with a subfield
- Citations without a known source
- 20.0%
- Share of Actual from citing works without a known source
- Reference coverage in 2021
- 87.7%
- Corpus-wide share of core-journal articles and reviews with at least one matched reference
OJR = Actual ÷ Expected
5 ÷ 6.121834 ≈ 0.82
Displayed values are rounded; OJR uses the unrounded expectation.