Use journal impact measures to compare the citation activity of journals, which can be useful for determining where to publish. These measures do not analyze the relative impact of individual authors.
The h-index is an attempt to quantify the research output of people. The h-index is the number of an author's papers n that each have at least n citations.
**NOTE: Each of the tools listed below calculates the h-index based solely on citations contained in that database. If the database doesn't include the journal(s) your paper(s) is in, your h-index information may be inaccurate. Use tools wisely and with hefty skepticism.