IPv4 subnet planner
Visual Subnet Calculator
Free online tool to split and join IPv4 CIDR blocks, plan subnets, and calculate address ranges, usable IPs, and netmasks — instantly in your browser.
Subnet Plan
| Subnet | Netmask | Address Range | Useable IPs | Hosts | Split | Join |
|---|
The shaded join cells represent the visual split tree. Parent cells merge that block back together.