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Measure Your Research Impact-h-index, impact factor and more: Impact Factor, Journal Metrics, CiteScore Metrics
Click on Journal Citation Reports at the top of the page.
Type in the Go to Journal Profile box type and enter your publication name; in this case Circulation. If the journal has an impact factor you will see the title in the drop down menu. Click on it.
In results page you will several data sets including impact factor.
In this case Circulation has an impact Factor of 17.202 for 2015.
* Journal Citation Report (JCR) is a product of Clarivate Analytics
CiteScore is a family of eight indicators that offer complementary views to analyze the impact of all serial titles including journal in Scopus.This is another Journal metric that researchers can use to measure their impact. Keep in mind there are 22,000 title currently but more will be added.