VLAN Planner
Use this VLAN planner to sketch a VLAN ID, name, subnet, gateway, and usable address range before documenting switch and router changes.
Calculator
How to use this calculator
Enter the planning values that match your network, storage, or cloud scenario. Use realistic production assumptions when sizing anything that affects availability, performance, or cost.
Formula or calculation method
The planner applies the subnet prefix to the base address, calculates the broadcast address, and uses the first usable address as a common gateway suggestion.
Worked example
For VLAN 20 on 10.20.0.0/24, the suggested gateway is 10.20.0.1 and the usable host range is 10.20.0.1 through 10.20.0.254.
Practical planning tips
- New office VLAN planning.
- Guest Wi-Fi subnet documentation.
- Lab and homelab network sketches.
Common mistakes to avoid
- Choosing a subnet too small for growth.
- Reusing VLAN IDs across conflicting domains.
- Forgetting DHCP reservations, gateways, and infrastructure addresses.
Frequently asked questions
Can I use this as final change control?
Use it as a planning aid, then verify against your network standards and live routing.
Why is the first IP suggested as a gateway?
Many networks use the first usable address for the gateway, but your standard may differ.