Abstract: A method and apparatus calculate a page table index from a virtual address. Employs a combined hash algorithm that supports two different hash page table configurations. A “short format” page table is provided for each virtual region, is linear, has a linear entry for each translation in the region, and does not store tags or chain links. A single “long format” page table is provided for the entire system, supports chained segments, and includes hash tag fields. The method of the present invention forms an entry address from a virtual address, with the entry address referencing an entry of the page table. To form the entry address, first a hash page number is formed from the virtual address by shifting the virtual address right based on the page size of the region of the virtual address.