process virtual address space

Question

I am reading some text about about the virtual address space of a process and it says that

If we have virtual address that are 32 bits long, the virtual address space of the process can be up to 4 GB.

This may be a silly question but how is 4 GB calculated? How do you work it out from 32 bits?

Answer 1

2 to the power of 32 is what gives you 4 GB. So with 32 bits, you can refer a memory area of up to 4 Giga bytes of addresses.