Fdisk disk size issue on RHEL 4

[Anne Moore]

Greetings All

I'm using FDISK to slice up my RHEL 4 servers. However, when I input, for
instance, "+50000M" for a 50 GIG partition, it actually only shows 46 GIG's
after the partition is complete. This is upsetting my customer who believe
I'm not doing things correctly. 

How do I determine how to get exactly the storage amount specified while
using fdisk?

Thank you for you expert assistance.

Anne