Summary: The development of the Semantic Web has encouraged the creation of ontologies in a great variety of domains. Web users currently looking for ontologies in order to incorporate them into their systems, just use their experience and intuition. This makes it difficult for them to justify their choices. Mainly, this is due to the lack of methods that help the user to measure that the most appropriate ontologies for the new system are. To solve this deficiency, this work proposes a method which allows the users to measure the suitability of the existent ontologies, regarding the requirements of their systems.