The Kahler metric for chiral matter fields plays a crucial role in the computation of soft supersymmetry breaking terms in string compactifications. Due to its non-holomorphic nature, this is difficult to compute in Calabi-Yau backgrounds. I describe techniques that allow the modular weights of the Kahler metric to be computed in IIB string compactifications. This is done by relating the modular dependence of the Kahler metric to that of the physical Yukawa couplings. I briefly discuss the applications to soft terms and neutrino masses.