A method for calculating a block cache size for a host process or application on a computer based at least upon virtual memory page evictions and/or virtual memory page reclamations for the computer. A virtual memory page eviction is the act of removing the contents of a physical memory page for the purpose of loading it with the contents of another virtual memory page. A virtual memory page reclamation is the return of a page to a working set that was previously removed by the operating system due to memory constraints. The page must not have been evicted. Additional fundamental properties of the application and the computer may be used, such as available physical memory on the computer, total physical memory, and block evictions. A block eviction is the act of removing the contents of a block from the block cache for the purpose of loading it with new contents.