IP Calculator

ipcalc takes an IP address and netmask and calculates the resulting broadcast, network, Cisco wildcard mask, and host range. By giving a second netmask, you can design subnets and supernets. It is also intended to be a teaching tool and presents the subnetting results as easy-to-understand binary values.

Enter your netmask(s) in CIDR notation (/25) or dotted decimals (255.255.255.0). Inverse netmasks are recognized. If you omit the netmask ipcalc uses the default netmask for the class of your network.

The wildcard is the inverse netmask as used for access control lists in Cisco routers.

Do you want to split your network into subnets? Enter the address and netmask of your original network and play with the second netmask until the result matches your needs.
Address (Host or Network) Netmask (i.e. 24) Netmask for sub/supernet (optional)
/ move to:

 No host given
 No netmask given (using default netmask of your network's class)

 



Address:   192.168.0.1           11000000.10101000.00000000 .00000001
Netmask:   255.255.255.0 == 24   11111111.11111111.11111111 .00000000
Wildcard:  0.0.0.255             00000000.00000000.00000000 .11111111
=>
Network:   192.168.0.0/24        11000000.10101000.00000000 .00000000 (Class C)
Broadcast: 192.168.0.255         11000000.10101000.00000000 .11111111
HostMin:   192.168.0.1           11000000.10101000.00000000 .00000001
HostMax:   192.168.0.254         11000000.10101000.00000000 .11111110
Hosts/Net: 254                   (Private Internet)

Thanks to http://www.netzwerkinfo.de/daemons/ for this ip calculator icon :-)