IPv4 range expander

Given a start and an end IPv4 address, this tool calculates a valid IPv4 subnet along with its CIDR notation.

Old Value
New Value
Start address
192.168.1.1
192.168.0.0
End address
192.168.6.255
192.168.7.255
Addresses in range
1,535
2,048
CIDR
192.168.0.0/21