We present a phenomenological analysis of p^±-Ca elastic scattering at 400, 500 and 672 MeV. The analysis is made within the framework of the diffraction model using parameterized phase shift function. Good agreement with the experimental data is achieved, at all energies. Using the parameter values of the p-⁴⁰Ca phase shift function we calculate the radius parameter of the Helm's model density for ⁴⁰Ca