As the sheer volume of new knowledge increases, there is a need to find effective ways to convey and correlate emerging knowledge in machine-readable form. The success of the Semantic Web hinges on the ability to formalize distributed knowledge in terms of a varied set of ontologies. We present Pan-Onto-Eval, a comprehensive approach to evaluating an ontology by considering its structure, semantics, and domain. We provide formal definitions of the individual metrics that constitute Pan-Onto-Eval, and synthesize them into an integrated metric. We illustrate its effectiveness by presenting an example based on multiple ontologies for a University.