Different measures are used for ranking journals in various disciplines. Here are some places to start:

Journal Citation Reports (JCR) (see link below) ranks journals in the sciences and social sciences based on a proprietary formula of the impact articles published in those journals have within a specific field. This "Impact Factor" ^tm is determined by the number of times articles in a journal are cited, how quickly articles are cited by others, and other criteria. Read more about the Clarivate Analytics Impact Factor on the Thomson Reuters website (see link below).  

Cabells Education Directory (see link below) covers journals in the fields of curriculum and methods, educational psychology and administration, and educational technology and library science. Cabell's gives in-depth information on acceptance rates, manuscript guidelines, relative prestige, and the intended audience. 

Read about more options for journal rankings on our Scholarly Metrics research guide (see link below). You can also contact your subject librarian for expert help with identifying top journals in your research area.