A simple method for calculating the ground-state energy of excitons confined in spherical quantum dots is presented. The exciton trial wave function is taken as a product of the ground-state wave functions of the unbound electron and hole in the QD, with a correlation function that depends only on electron–hole separation. A renormalized Schrödinger equation for the correlation function is deduced by using the variational principle. Both the differential equations for the unbound electron (hole) wave function in the QD and for the correlation function are solved numerically by means of the trigonometric sweep method. The ground state binding energies of an exciton in a GaAs–(Ga, Al)As spherical QD as a function of the dot radius are calculated for the models of square-well, soft-edge-barrier and double-step potentials.