How this calculator works
This calculator finds IPv4 network address, broadcast address, subnet mask, and usable host range from an IP address and CIDR prefix. Enter an IPv4 address and CIDR prefix to see the network details. Use it for network planning, IP address management, and subnet design. The key inputs are an IPv4 address and a CIDR prefix. The output is the network address, broadcast address, subnet mask, first usable host, last usable host, and total usable hosts. Real-world applications include network administration, IT planning, subnet design, and IP address management. The calculator converts the IPv4 address to a 32-bit integer, applies the CIDR mask, and converts network values back to dotted decimal. Prefixes /31 and /32 follow the common usable-host convention. This calculator is for IPv4 CIDR notation only. Use it as a quick reference and verify with network documentation and device requirements.