How to find impact factors
The impact factor of a journal is the average number of times that papers published in that journal have been cited during a specific period. The higher the impact factor the more prestigious the journal is considered to be. The impact factor is computed by dividing the number of citations received in a specific year by the number of articles published in the two preceding years. This number only acquires meaning if it is compared to the impact factors of other journals in the same discipline.
Exact and social sciences
The impact factors of journals from the exact and social sciences can be found in the database Web of Science > Additional resources > Journal Citation Reports.
Law Journals: Submissions and Ranking
In the field of law and jurisprudence there is the freely accessible website Law Journals: Submissions and Ranking. The impact factors of law journals can be found here.