๐Subnet / CIDR Calculator
Enter an IPv4 address and CIDR prefix length to find network details.
Free Subnet / CIDR Calculator
This subnet calculator takes an IPv4 address and CIDR prefix length (like /26) and finds the subnet mask, network address, broadcast address, the range of usable host addresses, and the total number of usable hosts.
CIDR notation compactly expresses how many bits of an IP address are the network portion โ a /24 means the first 24 bits identify the network, leaving 8 bits (256 addresses, 254 usable) for hosts. The calculator converts the prefix into the corresponding subnet mask and derives every other value from it.
Below the main result, a full table shows every possible prefix from /0 to /32 for your entered IP address, so you can compare network and broadcast addresses across every possible subnet size at a glance.
Useful for network engineering, subnetting practice, and infrastructure planning. Free, runs entirely in your browser.