In analyses of engineering systems, fundamental quest remains the distribution of certain entities (matter, energy) into the space. Thus certain definite forms are generated to serve a specific purpose. Bejan's constructal theory specifically deals with such optimal geometrical constructions. In this present article, equipartition theory is revisited from macroscopic standpoint. It is noted that equipartition principle is a corollary of a more generalized formulation-the constructal theory. It is seen that equipartition principle leads to certain power laws with which certain entities are distributed. This constitutes a deterministic law of nature in some finite length and time scale. Thus equipartition principle is to be recognized as an authentic basis of design for most efficient systems, which in turn obeys constructal principle of organization in nature. © 2005 Elsevier Ltd. All rights reserved.