Systems, methods, and media associated with function-based index tuning for queries with expressions are described. One exemplary method includes receiving a query for which an index is to be recommended. The query may include an expression, thus the method may include identifying an expression in the query and generating a set of column statistics related to the expression. The method may also include identifying candidate function-based indexes associated with the query, generating a set of function-based index statistics related to the candidate function-based indexes, and recommending a candidate function-based index.