The paper presents a method to calculate the phenotypic complexity of organisms. The phenotypic complexity of an organism is a measure of uncertainty associated with the size of the genome sequence, and is mathematically defined as the information entropy of the system. The amount of effective genomic information needed to produce a gene/protein sequences from a random sequence is at least the information entropy. The approach uses permutation and combination formulas to model the information needed to encode proteins for simple organisms like viruses, bacteria and other single celled organisms; and also extends the method to compute the information needed to produce differentiated cells and to construct spatial structures formed by the cells in higher organisms. The approach is not without interest, but several questions need to be addressed.