We study the necessary conditions for the formation of domains in helimagnets by calculating an exact expression for the classical magnetic dipolar energy associated to the magnetic helix, as a function of its pitch Lambda(0) and the system size. For magnets whose caliper dimensions exceed Lambda(0), we show that the dipolar energy density vanishes except at a region of depth Lambda(0) near the surface of the system. Thus, effectively, the dipolar magnetic energy is a skin effect which scales with the surface of the system. Consequently, the formation of domains becomes, in this case, energetically unfavorable. On the other hand, as the helimagnet smallest caliper dimension becomes comparable to Lambda(0), the dipolar energy crossover to a volume effect and, just like in a ferromagnet, for large enough systems the presence of domain walls reduces the dipolar energy and hence induces the formation of domains.