IPv4 Subnet Calculator
Easily calculate network ranges and broadcast addresses.
How to Use the Subnet Calculator
A subnet calculator is an essential networking tool used by system administrators to divide a larger network into smaller, more efficient sub-networks. Just enter an IP address along with its CIDR prefix (e.g., 192.168.1.0/24) and instantly compute network ranges.
Network Address
The very first address in the subnet. This IP is reserved to identify the network itself and cannot be assigned to a computer.
Broadcast Address
The last address in the subnet. It is used for sending data packets to all devices on that network simultaneously.
Subnet Mask
The dotted-decimal representation of your CIDR prefix (e.g., 255.255.255.0), used by devices to determine which subnet they belong to.
Host Range
The specific range of IP addresses you can safely use and assign to devices like computers, phones, and servers.
Why is Subnetting Important?
If you connect all devices to a single massive network, broadcast traffic can overwhelm the network, causing slowdowns. Subnetting breaks the network down into logical segments. For example, a business might create one subnet for its internal employees, a separate subnet for guest Wi-Fi, and another for security cameras. This isolation ensures that guest traffic cannot interfere with secure internal data.