How many networks and addresses are available for class b ip addresses?

First octet rule for each class:

Class A: 0xxxxxxx

Class B: 10xxxxxx

Class C: 110xxxxx

Class A range is 0 - 127

0.0.0.0 and 127.0.0.0 are not "routable" IP addresses. One defines all networks and the other is the loopback. We have a total of 126 usable networks and 16,777,214 usable hostaddresses per network. There are even less if we don't count the private address of 10.0.0.0 (RFC 1918).

Class B range is 128 - 191

There are 16,384 total networks in this class; that's including the private addresses of 172.16.0.0 - 172.31.0.0 (RFC 1918). There are a total of 65,534 usable host addresses per network.

Class C range is 192 - 223

There are 2,097,152 total networks in this class; that's including the private addresses of 192.168.0.0 - 192.168.255.0 (RFC 1918). There are 254 usable hosts addresses per network.