How is the 5-year impact calculated?
The 5-year impact factor for year X equals the citations received in year X to items published in years X-1 through X-5, divided by the number of citable items published in those five years.
How should I interpret impact factors?
Longer windows (3-, 5-, 10-year) emphasize sustained influence and reduce volatility. Use them to compare journals within the same field rather than across fields.
