The classical Plücker formulas are the relations between the order, class and genus of a given smooth projective algebraic plane curve which were first established by J. Plücker (1834) and later generalized by M. Noether (1875) for projective algebraic plane curves which may have ordinary singularities. A century later, these relations have been extended to the general case of projective algebraic curves by M. Rosenlicht (1952) and to the local case of analytical curves by Milnor (1968). In this note we shall establish such a relation for the affine case of algebraic plane curves.