Visual Subnet Calculator
This Visual Subnet Calculator helps you quickly divide IPv4 networks, visualize them clearly, and split or join subnets with a single click. It also displays key details like IP address range, subnet mask, and the number of usable hosts for each subnet.
Base Network Setup
Invalid. Only IPv4 is supported.
Invalid IPv4 mask format.
Interactive Subnet Map
Show Columns:
| Hierarchy | Network | First Usable IP | Last Usable IP | Broadcast | Total Usable Host | Total Available Host | Netmask | Wildcard | Split / Join |
|---|
How to Use the Visual Subnet Calculator
This tool acts as an interactive canvas for Variable Length Subnet Masking (VLSM). Instead of blindly calculating numbers, it allows you to dynamically break down a large chunk of IP space into perfectly sized, non-overlapping networks—while tracking the full split hierarchy with connected flowchart tree lines.
- Step 1: Set Your Base Network. Define your starting parent block using the inputs at the top (e.g., a
10.0.0.0/16block). The table will generate a single row with a colored dot in the Hierarchy column representing that entire network. - Step 2: Splitting Subnets. Click the Split icon on any row. The engine instantly borrows one network bit, dividing that subnet perfectly in half. The Hierarchy column draws a connected flowchart tree line from the parent dot down to each child dot—vertical lines show ancestry, horizontal branches show sibling splits, and each depth level gets its own color so you can instantly see how deep a subnet sits in the tree.
- Step 3: Joining Subnets. Click the Join icon to reverse a split. You can only join perfect binary "siblings" (created from the same parent). When joined, the two child branches collapse back into a single parent dot, and the tree lines reconnect automatically.
- Step 4: Customize & Export. Use the "Show Columns" toggles to hide data you don't need, then click the Copy or Download CSV buttons to export your completed VLSM hierarchy map directly to your clipboard or spreadsheet.