Using the ab initio methods of the density functional theory, the influence of hydrostatic pressure on the elastic properties of magnesium, zinc, cadmium, calcium carbonates with the structure of calcite, double calcium-magnesium carbonates, cadmium-magnesium, calcium-zinc with the structure of dolomite and calcium, strontium, lead, barium carbonates with the structure of aragonite is studied. Derivatives with respect to pressure for elastic constants and linear moduli, polycrystalline compression and shear moduli, transverse and longitudinal velocities of acoustic waves are obtained. Dependences on the cation radius for the ratio of the elastic constant to its pressure derivative, the velocity of longitudinal waves to its pressure derivative, the pressure derivative of the bulk modulus, the pressure derivative of the shear modulus, and other parameters of a number of metal carbonates have been established.