Frequently Asked Questions
What is a subnet calculator?
A subnet calculator takes an IP address and CIDR prefix length (like /24) and computes all related subnet information: network address, broadcast address, usable host range, subnet mask, wildcard mask, and total number of hosts. It helps network administrators plan and troubleshoot IP addressing.
What is CIDR notation?
CIDR (Classless Inter-Domain Routing) notation uses a slash followed by a number (e.g., /24) to indicate how many bits of the IP address are used for the network portion. A /24 means the first 24 bits are the network, leaving 8 bits for hosts (254 usable addresses). Lower CIDR numbers mean larger networks.
What is the difference between network address and broadcast address?
The network address is the first address in a subnet (all host bits set to 0) and identifies the subnet itself. The broadcast address is the last address (all host bits set to 1) and is used to send data to all hosts in the subnet. Neither can be assigned to a device, which is why usable hosts are 2 fewer than total addresses.
Is this tool free to use?
Yes, this IP subnet calculator is completely free. It runs entirely in your browser with no data sent to any server. No signup, no limits, no tracking of your IP calculations.