Supersymmetric versions of induced-gravity inflation are formulated within Supergravity ( SUGRA ) employing two gauge singlet chiral superfields . The proposed superpotential is uniquely determined by applying a continuous R and a discrete \mathbb { Z } _ { 2 } symmetry . We also employ a logarithmic Kähler potential respecting the symmetries above and including all the allowed terms up to fourth order in powers of the various fields . When the Kähler manifold exhibits a no-scale-type symmetry , the model predicts spectral index n _ { s } \simeq 0.963 and tensor-to-scalar r \simeq 0.004 . Beyond no-scale SUGRA , n _ { s } and r depend crucially on the coefficient k _ { S \Phi } involved in the fourth order term , which mixes the inflaton \Phi with the accompanying non-inflaton superfield S in the Kähler potential , and the prefactor encountered in it . Increasing slightly the latter above ( -3 ) , an efficient enhancement of the resulting r can be achieved putting it in the observable range favored by the Planck and B icep2 / Keck Array results . In all cases , imposing a lower bound on the parameter c _ { R } , involved in the coupling between the inflaton and the Ricci scalar curvature , inflation can be attained for subplanckian values of the inflaton while the corresponding effective theory respects the perturbative unitarity . Published in PoS CORFU 2014 , 156 ( 2015 ) .