Make sure sn + h from the above two steps does not exceed the number of host bits available in the network available. If the sum of sn and h exceed the available host bits then you will require another network of the same class or a network of a higher class. In our example we have 8 bits of host addresses available in 192.168.10.0 255.255.255.0 network. Our sn+h is 3+5 that gives us 8.