NetCalc Pro Quickstart

1 / Set the parent CIDR

Top of the sidebar. The Network field takes a dotted-quad (10.0.0.0). The Mask field is the CIDR prefix length (0–32). Together they draw the outer block your tree lives inside.

The mask never grows your tree it only frames it. Splitting is how you create deeper subnets.

2 / Pick a cloud provider

The Provider select under Network/Mask decides how many IPs each subnet loses to reserved addresses.

AWS / Azure / Huawei / IBM reserve 5 per subnet.
GCP reserves 4.
Oracle (OCI) reserves 3.
Alibaba / Standard reserve 2.

Every host-count shown in the app (stats panel, capacity analysis, cheat sheet, cost estimator) bakes this in.

3 / Split the tree

In the Subnet table, click Split on any row to halve it into two /n+1 children. Split repeatedly to build a VLSM tree, or use the VLSM Wizard (Tools →) to plan from a list of host counts.

Join a row to collapse two siblings back into their parent. Hover the Join button to preview which rows would fold together.

4 / Label the leaves

Double-click the Subnet / Label column on any leaf to open the Label Editor. You can set:

Label the human name (prod-web, bastion).
Notes free-form text carried into exports.
VLAN a numeric id. The Radar drawer flags duplicate VLANs across every open workspace live as you edit.
AZ availability zone hint; Terraform export uses it when placing the subnet in a region.

Need to tag many at once? The Bulk label editor under Tools shows one row per leaf with all four fields in a single table.

5 / Export

The Export menu (top right of the subnet table) offers eleven formats. Start with one of:

JSON round-trippable via Import.
CSV spreadsheet.
Markdown documentation paste.
Infrastructure as Code… Terraform HCL for AWS, Azure, GCP, Huawei, Alibaba, Oracle, IBM.
Print / PDF browser print dialog.

6 / Share a link

Share in the sidebar footer copies a URL that encodes the entire tree + labels + VLANs in Base64. Paste it anywhere; opening it restores the exact workspace. No backend involved.