IPv4 Subnet Calculator

Calculate subnet mask, network address, broadcast address, host range, and number of usable hosts from any IPv4 CIDR notation.

CIDR Notation
192.168.1.0/24
Network Address
192.168.1.0
Subnet Mask
255.255.255.0
Wildcard Mask
0.0.0.255
Broadcast Address
192.168.1.255
First Usable Host
192.168.1.1
Last Usable Host
192.168.1.254
Usable Hosts
254
Total Addresses
256
IP Class
Class C

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How to Use This Tool

Enter an IPv4 address with CIDR prefix length (e.g. 192.168.1.0/24) and click Calculate. The tool computes network address, broadcast address, subnet mask, wildcard mask, host range, and total usable hosts.

Common Use Cases

  • Plan IP address allocation for a new network segment
  • Verify subnet configurations on routers and firewalls
  • Calculate available host addresses before provisioning servers
  • Study for networking certifications (CCNA, CompTIA Network+)

Frequently Asked Questions

What is CIDR notation?

CIDR (Classless Inter-Domain Routing) notation represents an IP address and its associated network mask as a single string, e.g. 192.168.1.0/24. The number after the slash indicates how many bits are used for the network portion.

How many usable hosts are in a /24 subnet?

A /24 subnet has 256 total addresses (2^8). Subtracting the network address and broadcast address leaves 254 usable host addresses.

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 on the subnet.

What is a wildcard mask?

A wildcard mask is the inverse of a subnet mask. It is used in access control lists (ACLs) to specify which bits of an IP address must match. For a /24 subnet mask of 255.255.255.0, the wildcard mask is 0.0.0.255.