IBM® SPSS® Amos™ 28
Bollen's (Bollen, 1989b) incremental fit index ( IFI) is given by
,
where 
and 
are the discrepancy and the degrees of freedom for the model being evaluated, and 
and 
are the discrepancy and the degrees of freedom for the baseline model.
IFI values close to 1 indicate a very good fit.
Use the \ifi text macro to display IFI on a path diagram.
