Using two different full-potential ab initio techniques we introduce a very simple rule based on the number of broken first-neighbor bonds to determine the surface energies of the noble metals and fcc transition metals . When a bond is broken, the rearrangement of the electronic charge for these metals does not lead to a significant change of the remaining bonds. Thus the energy needed to break a bond is independent of the surface orientation, so that the anisotropy of the surface energies is determined by the number of broken nearest-neighbors bonds. While this rule is well obeyed for the fcc noble ans transition metals, significant deviations occur for the fcc sp-metals. This novel finding can lead to the development of simple models to describe the energetics of a surface like step and kink formation, crystal growth, alloy formation, equilibrium shape of mesoscopic crystallites and surface faceting.