ABSTRACT A new concept for the calculation of the bearing capacity of shallow foundations is presented. The Terzaghi-Buisman equation was transformed and extended to include all possible load cases. The shape ratio was rigorously defined. Torsional moment factors considering eccentric horizontal loads were proposed and defined for the first time, in order that complete 6-dimensional interaction diagrams could be derived. The effect of embedded depth was also investigated and considered for special factors. The influence of cohesion was derived from Caquot’s theorem of the corresponding states of stress. Experimental investigations with some interesting results are presented. A new calculation scheme is presented at the conclusion of the paper.