This paper gives a classification of arithmetical affine complete varieties of finite type up to categorical equivalence. It is proved that two such varieties are equivalent as categories if and only if their weakly diagonal generators have isomorphic monoids of bicongruences. Moreover, it is proved that the monoids appearing in this situation are precisely the inverse factorizable monoids with zero, with distributive lattice of idempotents, and satisfying a certain idempotent-unit condition (IU).