Abstract: In different conditions, there are different planned elevations for the bulk wide area earthwork. On the basis of theory presented by professor Leiboumils (Bulgarian), with respect to calculation of the optimum planned elevation which is not subject to any condition, five theorical formulae for calculating the optimum planned elevation in different special conditions are suggested: first, the distance of each point is equal in the ground of square; second, the planned area without retaining a height of given point (P); third, the planned area must retain a inclined angle in one direction; fourth, the planned area must retain the height h₁ and h₂ for two given points; fifth, the planned area must retain horizontal. In this way, the volume of earthwork can be the least and the calculation can also be simpler if calculation is made in accordance with the formulae under the original condition.