Subnet Calculator 🌐
Calculate network address, broadcast, host range, and capacity.
Network Address
Broadcast Address
Usable Host Range
Total Hosts
Usable Hosts
What is a Subnet Calculator?
A subnet calculator is a network utility tool that allows you to calculate subnet masks, network addresses, broadcast addresses, and the range of usable host IP addresses. It simplifies the process of dividing a larger network into smaller sub-networks (subnetting), ensuring efficient IP address allocation and improved network performance and security.
Understanding IPv4 and CIDR Notation
IPv4 addresses are 32-bit numbers typically written in decimal format (e.g., 192.168.1.1). To determine which part of the IP address represents the network and which part represents the host, a subnet mask is used.
Classless Inter-Domain Routing (CIDR) notation is a more compact way of expressing the subnet mask. Instead of writing out the full mask (like 255.255.255.0), CIDR notation appends a forward slash followed by the number of network bits (e.g., /24). The remaining bits are used for host addresses.
- Network Address: The first address in the subnet, used to identify the network itself.
- Broadcast Address: The last address in the subnet, used to send data to all devices within the network.
- Usable Hosts: The range of addresses between the network and broadcast addresses that can be assigned to devices.
IPv6 Subnetting
IPv6 was developed to address the exhaustion of IPv4 addresses, offering a vastly larger 128-bit address space. Subnetting in IPv6 works on the same principles as IPv4 but uses hexadecimal notation and typically focuses on assigning prefixes rather than dealing with complex variable-length subnet masks. The standard prefix length for a local network in IPv6 is /64, which provides an unimaginable number of host addresses (18 quintillion).