The main result of the paper is the following: given an extension L of S4 with the finite model property, it is possible to define a Kripke model M which contains less than 8 points such that, for each pair A, A’ of modalities, \(L\vdash A\equiv A'\) if and only if \(M\vDash A\equiv A'\). Furthermore, it is shown that only 6 among all the possible charts of modalities are satisfied by at least one extension of S4 with the finite model property.