CIDR to network, broadcast, wildcard, usable range, and VLSM subnetting. Built for network engineers who want answers fast.
Accepts IPv4 with CIDR (e.g., 10.0.0.0/8). Defaults to /24 if no mask is given.
Subnets are allocated in the order you enter, sorted internally by size.
Enter a CIDR and click Calculate to see subnet details.
Drop in any CIDR and get network, broadcast, wildcard, usable range, and host count instantly.
Give it a base network and a list of required hosts. It carves out the right prefix lengths and prints the full subnet table.
Paste two CIDRs and find out whether they collide — useful before you merge networks or add a new VLAN.
Once the page is loaded, yes. All calculations happen in your browser; no server is involved.
Not yet — this version is focused on IPv4 subnetting and VLSM, which is where most day-to-day network work still happens.
The tool allocates subnets by required size to minimize wasted address space. The result table is shown in that order.