IP Subnet Calculator (CIDR)
Enter a CIDR block like 192.168.1.0/24 to see the network address, mask, broadcast and host range.
Frequently Asked Questions
What do CIDR and the / notation mean?
The number after / shows how many bits are fixed for the network part; e.g. /24 means 24 network bits and 8 host bits (254 usable hosts).
What is the difference between the network and broadcast address?
The network address is the first address and identifies the network itself; broadcast is the last address used to send to all hosts at once. Neither is assigned to a device.
Why are usable hosts two fewer?
Because the first address (network) and last address (broadcast) are reserved and not assigned to devices.