Journal Citation Reports ranks journals based on their impact factor within their disciplinary category.
To find rankings for a journal, search for and select an individual journal. Then SCROLL DOWN - the rankings are relatively hidden under a Rank link, as shown below. Click on Rank, and you'll see the specific ranking for the subject category (or categories) displayed.
SJR discipline rankings lists all of the journals in a discipline or subdiscipline based on their SJR. These rankings are available only through SCImago's website, scimagojr.com
To find rankings from the home page, click on "Journal Rankings", then select a Subject Area and/or Subject Category. Make sure it says "Order by: SJR" in the dropdown.
The list will also display the quartile ranking for each journal in the category, or which 25% the journal belongs to. The top 25% of journals in that category will show with a green Q1, then a yellow Q2 for the next 25% of journals, and so forth.
An individual journal title can also be searched for - clicking on an individual journal title will show all of the subject areas/categories it belongs to.
The ranked list from the Subject Category "Library and Information Science" is shown above.
Google Scholar rankings list all of the journals in a discipline or subdiscipline based on the H5-index or H5-median. These rankings are available through Google Scholar Metrics.
To find rankings from the home page, click on one of the categories under "English" (or select another language), then click "Subcategories" for subdisciplines. The default ranking is by H5-index, but can be resorted by H5-median by clicking on the top of the appropriate column.
Google Scholar Metrics can also be searched by keyword, pulling up an informal ranking list of journals with that word in the title. Below is a chart of the first few journals with the word "interdisciplinary" in the title, sorted by H5-index.