IP Subnet Calculator

What is IP Subnetting?

IP subnet calculation breaks down a CIDR (Classless Inter-Domain Routing) notation address like 192.168.1.0/24 into its network details. The /24 is the prefix length (subnet mask in bits) — it tells you how many bits are fixed for the network portion and how many are available for host addresses. A /24 network has 256 addresses (2^8), of which 254 are usable for hosts (the first is the network address and the last is the broadcast address). Subnet calculation is essential for network planning, firewall configuration, VPC/VPN setup in cloud environments (AWS, GCP, Azure), and understanding routing tables.

How to Use the IP Subnet Calculator

Enter an IP address with CIDR notation (e.g. 192.168.1.0/24) in the input field.
The tool instantly calculates and displays: network address, broadcast address, subnet mask, wildcard mask, usable host range, and total host count.
Binary representations of the address and mask are shown for visual understanding.
Use the results to configure routers, firewalls, security groups, or network documentation.

Frequently Asked Questions

What does /24 mean in an IP address? /24 means the first 24 bits of the IP address are the network prefix, leaving 8 bits for host addresses. This gives 2^8 = 256 total addresses (254 usable). The subnet mask equivalent is 255.255.255.0.

What is the difference between a network address and broadcast address? The network address (e.g. 192.168.1.0) is the first address in the subnet and identifies the network itself — it cannot be assigned to a host. The broadcast address (e.g. 192.168.1.255) is the last address, used to send packets to all hosts in the subnet simultaneously.

What is a wildcard mask? A wildcard mask is the inverse of the subnet mask. Where the subnet mask has 1s, the wildcard has 0s. Wildcard masks are used in ACLs (Access Control Lists) on Cisco routers to specify which bits of an address must match a rule.

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