The XQuery language is the standard query language for XML. The result of XQuery queries are typically XML documents in other formats. We introduce the term output schemas of an XQuery query, which represents those schemas, to which the resultant XML documents of the considered XQuery query conform to. Output schemas of XQuery queries can be used to automatically detect the XQuery query, which has been used for querying, of target XML documents or to reason on the output schema without access to the resultant XML documents for a static analysis of the used XQuery query. In this paper, we describe the automatic determination of an output schema of a given XQuery query. The input of our proposed output schema generator is the used XQuery query and the schema of the input XML documents.