Subnet Calculator
CIDR Calculator for Network Professionals
Subnet Calculator
How to Use
Enter an IPv4 address and either a subnet mask (e.g., 255.255.255.0) or CIDR notation (e.g., /24). The calculator will determine the network address, broadcast address, usable host range, and more.
CIDR Reference Chart
Common CIDR Notations
About CIDR Notation
CIDR (Classless Inter-Domain Routing) notation represents an IP address and its associated routing prefix. The notation consists of an IP address, followed by a slash ('/'), followed by a number (e.g., 192.168.1.0/24). The number indicates how many leading bits are set in the subnet mask.
Network Addressing Basics
IP Address Classes
Default mask: 255.0.0.0 (/8)
Default mask: 255.255.0.0 (/16)
Default mask: 255.255.255.0 (/24)
Multicast addresses
Reserved for experimental use
Private IP Address Ranges
Special IP Addresses
Key Network Terms
Network Address: The first address in a subnet, identifies the network itself.
Broadcast Address: The last address in a subnet, used to send to all hosts.
Host Range: The usable IP addresses between network and broadcast addresses.
Subnet Mask: Defines which portion of an IP address is network and which is host.
Wildcard Mask: The inverse of the subnet mask, used in access control lists.
A powerful and easy-to-use Subnet Calculator and CIDR Calculator designed for network administrators, IT professionals, and students. Input an IP address and subnet mask or CIDR notation to instantly calculate the network address, broadcast address, usable host range, total usable hosts, and wildcard mask. Ideal for learning and managing IP addressing in IPv4 networks.