Enter an ipv4 address below, and exit the field (or presssing enter might work).
Then select how many bits to borrow for subnetting, and watch the data change.

IP Address:
IP Class:
Default subnet mask:
Custom subnet mask:
Total number of subnets:
Total number of host addresses:
Number of usable addresses:
Number of bits borrowed:
Select a number below to display the range of the subnet.
Subnet:
Network address:
First usable host address:
Last usable host address:
Broadcast address: