Subnet Plan Studio

Subnet Plan Studio turns an IPv4 address block and a list of host requirements into a clear, deterministic VLSM allocation without scanning a network or contacting a server. Create multiple named plans, enter a base IPv4 address and prefix, then add the host groups you need. The planner allocates the largest requirements first, aligns each subnet boundary, and shows the assigned CIDR, usable range, broadcast address, requested hosts, and available capacity. See allocated addresses, remaining addresses, and overall use at a glance. Edit group names, notes, and host counts as the design changes. If the base network is invalid or too small, the app fails closed and explains what needs attention instead of presenting a partial plan as complete. When the plan is ready, export the same calculated result as a named CSV or Markdown file through the iOS share sheet. Projects are stored locally on your device so you can return to them without an account. Subnet Plan Studio is a one-time purchase. There are no subscriptions, in-app purchases, ads, accounts, analytics SDKs, tracking, cloud sync, network scanning, router access, or developer-operated servers. The app plans IPv4 subnets only. It does not discover devices, configure routers, test reachability, reserve addresses on a DHCP server, or verify a live network.