Ca-substituted BaTiO 3 with extended homogeneity range upto ∼50 mol% CaTiO 3 have been prepared by three different chemical routes namely carbonate-oxalate (COBCT), gel-carbonate (GCBCT), and gel-to-crystallite conversion (GHBCT) followed by heat treatment above 1150 °C. X-ray powder diffraction (XRD) data show continuous decrease in the tetragonal unit cell parameters as well as c 0/ a 0 ratio with CaTiO 3 content, which are in accordance with the substitution of smaller sized Ca 2+ ions at the barium sites. The microstructure as well as the dielectric properties are greatly influenced by the cationic ratio, α=(Ba+Ca)/Ti. The grain size decreases with CaTiO 3 content for the stoichiometric samples ( α=1), whereas ultrafine microstructure is observed in the case of off-stoichiometric samples ( α>1) for the whole compositional range of CaTiO 3 concentrations. Sharper ε r– T characteristics at lower calcium content and broader ε r– T with decreased ε max, in the higher calcium range are observed in the case of α=1. Whereas nanometer grained ceramics exhibiting diffuse ε r– T characteristics are obtained in the case of α>1. The positive temperature coefficient of resistivity (PTCR) is realized for barium calcium titanate ceramics having 0.3 at.% Sb as the donor dopant for higher CaTiO 3 (typically 30 mol%) containing samples ( α=1), indicating that Ca 2+ ions do not behave as acceptors if they were to substitute at the Ti 4+ sites. Whereas the off-stoichiometric ( α>1) ceramics retained high resistivity, indicative of the Ti-site occupancy for Ca 2+ in fine grain ceramics.