We present an overall empirical formula that, after specification of its free parameters, describes precisely the mass spectrum of charged leptons and is suggested to reproduce correctly also the mass spectra of neutrinos, and up and down quarks (together, twelve masses with twelve specified free parameters are presented). Imposing a priori some constraints on three parameters, we predict three of lepton and quark masses, especially the taon mass as m(tau) = 1776.80 MeV. We also present a more theoretical argumentation in favor of our mass formula. In Appendix, an option of composite quarks is briefly outlined, where elementary color-triplet quark-like fermions are bound with a color-triplet isoscalar scalar boson (3* x 3* -> 3 color coupling). This option plays here the role of a theoretical hint at imposing a constraint a priori on a free parameter in our mass formula for quarks. The possibility of leptons composed from the same preons as are quarks is considered in brief (3* x 3 -> 1 color coupling).