A subnet calculator takes an IP address and CIDR prefix length (e.g., 192.168.1.0/24) and computes the network address, broadcast address, subnet mask, wildcard mask, and the full range of usable host addresses. InfraHub's calculator supports both IPv4 (32-bit) and IPv6 (128-bit) addresses, making it the only tool you need for modern dual-stack networking.

All computation runs in your browser using BigInt arithmetic — no data is sent to any server.

For IPv4, the tool applies bitwise AND between the IP address and subnet mask to derive the network address, then uses bitwise OR with the inverted mask to find the broadcast address. For IPv6, the same logic extends to 128-bit integers using JavaScript BigInt. CIDR notation (slash notation) is parsed to derive prefix length, and both short-form and expanded IPv6 formats are supported.

Cloud architects use subnet calculators when designing VPC address spaces in AWS, GCP, or Azure to ensure CIDR blocks don't overlap. Network engineers plan office LAN segments. System administrators verify that a given IP address falls within an allowed subnet before updating firewall rules. Students and exam takers use it to check manual subnetting calculations.