An economy mass formula, found recently for leptons and quarks as a se
miempirical relationship based on a Dirac square-root model proposed p
reviously for three fermion families, is supplemented by an ansatz con
cerning four mass scales appearing in this formula (in four cases of n
eurtrinos, charged leptons, up quarks and down quarks). Then, in the m
ass formula there remain only three free parameters that can be determ
ined from experimental values of m(e), m(mu) and \V(us)\. Nevertheless
, it predicts all other lepton and quark masses as well as quark mixin
g parameters in nice agreement with existing experimental data.