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Calculate network information, IP ranges, and usable hosts for any subnet.
Subnetting is the process of dividing a network into smaller network sections called subnets. It improves network performance, security, and address management.
Our IP Subnet Calculator is an essential tool for network engineers, IT professionals, and students to plan and manage IP networks. It allows you to calculate all critical network parameters based on an IP address and a subnet mask (or CIDR prefix). The tool instantly computes the Network Address, Broadcast Address, First and Last Usable IP Addresses, Total Number of Hosts, and the Subnet Mask in various formats including dot-decimal and binary. Whether you're designing a new network, subnetting a larger block, or studying for certification exams (CCNA, Network+), this calculator ensures precision and eliminates manual errors.
Enter an IP address (e.g., 192.168.1.1) and select a Subnet Mask (CIDR)Our calculator performs bitwise operations on the binary IP and MaskIt identifies the Network ID (first address) and Broadcast IP (last address)It calculates the range of valid/usable host IP addressesIt determines the total number of usable hosts per subnetResults are displayed in Decimal, Binary, and Hexadecimal formats
Plan IP allocation for office networks and VLANs, ensuring optimal subnet sizing to prevent address wastage.
Verify if devices reside on the same subnet, check for mask misconfigurations, and identify overlapping ranges.
Master binary subnetting concepts and validate manual calculations for CCNA, Network+, or other IT exams.
We don't log or store any IP addresses or search queries. Your privacy is hard-coded into our architecture.
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Results are generated in real-time through temporary memory, never written to persistent disks.
CIDR (Classless Inter-Domain Routing) notation is a compact way to represent an IP address and its associated network mask. It uses a slash followed by a number (e.g., /24), which represents the number of "1" bits in the subnet mask. For example, /24 is equivalent to the subnet mask 255.255.255.0. It simplifies network descriptions compared to writing out full dotted-decimal masks.
The formula for usable hosts is 2^n - 2, where "n" is the number of host bits (32 minus the CIDR prefix). We subtract 2 because the very first address is reserved as the "Network Address" and the very last address is the "Broadcast Address". For example, a /24 network has 8 host bits (32-24=8). 2^8 = 256. Subtracting 2 gives 254 usable host IP addresses.
A subnet mask is a 32-bit number that separates the IP address into the network portion and the host portion. It is used by computers to determine if another IP address is on the same local network or if traffic needs to be routed through a gateway. A "1" bit in the mask indicates the network part, and a "0" bit indicates the host part.
Private IP ranges (defined in RFC 1918) are reserved for internal networks (LANs) and are not routable on the internet. They include: 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16. Public IPs are unique across the entire internet. Our calculator works for both, but when designing a home or office network, you should almost always use private IP ranges.
In every IPv4 subnet, the first address (all host bits set to 0) is the Network Address used to identify the subnet itself. The last address (all host bits set to 1) is the Broadcast Address, used to send data to every device on that subnet simultaneously. Therefore, these two addresses cannot be assigned to individual devices like computers or printers.