The properties of excitons on three different conjugated polymers in solution are investigated both experimentally and theoretically. The theoretical description of the excitons is obtained by solving the electron-hole Bethe-Salpeter equation (BSE) for the polymers, starting from a calculation within density-functional theory. The calculated radiative lifetimes and polarizabilities of the excitons are compared with experimental results from time-resolved fluorescence decay and flash-photolysis microwave conductivity measurements. The quantitative agreement demonstrates the predictive power of the theoretical approach.