Reason for page sizes be powers of 2 always

Question

Why are always page sizes powers of 2?

 

Answer 1

Recall that paging is implemented through breaking up an address into a page & offset number. It is most capable to break the address into X page bits and Y offset bits, instead of perform arithmetic on the address to compute the page number and offset. Because each of bit position represents a power of 2, splitting an address among bits results in a page size which is a power of 2.