Q index is the quartile score of a journal or a paper. It can be classified into 4 categories -

Q1 - Top impactful 25% journal or paper

Q2 - Less impactful 25% journal or paper

Q3 - Lesser impactful 25% journal or paper

Q4 -Bottom impactful 25% journal or paper

Q index is the quartile score of a journal or a paper. It can be classified into 4 categories -

Q1 - Top impactful 25% journal or paper

Q2 - Less impactful 25% journal or paper

Q3 - Lesser impactful 25% journal or paper

Q4 -Bottom impactful 25% journal or paper

https://www.scimagojr.com/journalrank.php

Above is the link where you can check the Q-index of any SCI-indexed journal

There are four quartiles: Q1, Q2, Q3 and Q4. Q1 is occupied by the top 25% of journals in the list; Q2 is occupied by journals in the 25 to 50% group; Q3 is occupied by journals in the 50 to 75% group and Q4 is occupied by journals in the 75 to 100% group. Q4 is occupied by journals in the 75 to 100% group...

Web of Science

https://mjl.clarivate.com/mjl-beta/home

Q index is the quartile of a journal, i.e., Q1, Q2, Q3 and Q4. Each represnts 25% begining from 0 (Q4) to 100 % (Q1).

In science index, it is the quartile of a journal representing 25%, 50%, 75% and 100%.

It can be termed as field specific ranking. Q index defines the rank of a journal in a specific field, described as Q1, Q2, Q3, and Q4 with Q1 among top 25% journals in the field.

Q index defines the rank of a journal in a specific field. It describes ranking of the journal as as Q1, Q2, Q3, and Q4 where Q1 means the ranking among top 25% journals in the same field.

plz check it Web of Science

https://mjl.clarivate.com/mjl-beta/home

@James Adegboye

Q index simply means quartile index which is the ranking of any Journal or paper that belongs to a specific or particular field of discipline such as Q1, Q2, Q3 & Q4. There are parameters for measuring or ranking a journal (paper or article)

All the above inputs are correct and helpful.

Q index is correlated with SJR and impact factor , so Q1 journal means journal with high SJR and impact factor like lancet journal , and so with other Q levels

Journal ranking is widely used in academic circles in the evaluation of an academic journal's impact and quality. Journal rankings are intended to reflect the place of a journal within its field, the relative difficulty of being published in that journal, and the prestige associated with it. It can be classified into 4 categories Q1, Q2, Q3 and Q4 where Q1 denotes the ranking among top 25% journals in the same field.

All the responses are correct. However, I would like to point out that the same Journal can have different Q ranking in different sources like Scopus and Clavirate depending on the subject in which they are accounted for.

Q indicates the journal ranking . Example Q1 means the journal is in top 25% in ranking.

where can we find Q ranking of a journal?

This index pertains to the IF of a specific field, for example Quality Technology and Quantitative Management journal has been located in the first group (Q1) in its field in 2019 whereas it was in the last (Q4) category in 2018. This index is subject to more changes than IF and in some countries like IRAN is the most important index in evaluation of paper qualities.

Dear Rafiullah Khan you can find Q ranking of a journal on sciimago journal and country rank on below mentioned web address.

https://www.scimagojr.com/journalrank.php

In many universities, the academicians need to publish in Q ranking journals only to fulfil their KPI and mostly the journals are SCOPUS indexed (Q1 to Q4). Some journals are free and some are payment, to publish their research work.

Each subject category of journals is divided into four quartiles: Q1, Q2, Q3, Q4. Q1 is occupied by the top 25% of journals in the list; Q2 is occupied by journals in the 25 to 50% group; Q3 is occupied by journals in the 50 to 75% group and Q4 is occupied by journals in the 75 to 100% group.

https://www.scimagojr.com/journalrank.php