https://www.researchgate.net/post/How_is_impact_factor_calculated

Discovery reported in the journal publications by a single author or its co-authors is divided in equal mannerism because it was the contribution of all who have had made efforts or involve in the activity. Subsequently publish its results in the journal publications. Journal impact factor is also distributed by the author and co-authors equal basis.

It is interesting to say that journal impact factor is a measurement of the two-years average number of citations to the recent papers published in particular journal calculates recent two years publication period. The basic ideas of calculating journal impact factor first devised by “Eugene Garfield” founder of Institute of Scientific Information. Journal Impact is calculating since 1975. The equation for calculating the journal impact factor the number of citation received in the two preceding years for papers published in the particular journal divided by total number of papers published in the same preceding years

Impact Factor Calculation

Citation (year first) + Citation (Year two)

-----------------------------------------------------

Publications (Year fist) + Publications (year two)

Example

Impact Factor for the 2017

Citation 2017 + citation 2016

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Publications 2017+ Publication 2016

32400+ 35200

----------------

850 + 870

39.302

So the journal impact factor for the preceding years 2017 & 2016 (journal assumed) is 39.302

https://www.researchgate.net/post/How_is_impact_factor_calculated

Thank you so much for these informations.

With regards

Journal Impact Factor is from Journal Citation Report (JCR), a product of Thomson ISI (Institute for Scientific Information).

The impact factor for a journal is calculated based on a three-year period.

For example, the journal impact factor 2018 for a journal would be calculated as follows:

A = the number of times articles published in 2016 - 2017 were cited in indexed journals during 2018

B = the number of articles, reviews, proceedings or notes published in 2016 - 2017

Impact factor 2018 = A/B

(Journal impact factor 2018 will be published in 2019, because it can not be calculated until all of the 2018 publications received).

Please go through the attached article "Impact factors – the basics". Useful information on the following topics:

• What are impact factors?
• Calculation of impact factor
• Subject variation in impact factors
• What causes subject variation in impact factors? .

Regards