VLAN & Subnet Calculator
Calculate IP address allocation across VLANs with optimal subnet sizing, growth margin, and utilization analysis.
Inputs
%
Results
Subnet CIDR
25 bits
Hosts per Subnet
126
Total Usable IPs
504
Devices per VLAN50
Devices + Growth65
Total IPs Allocated512
IP Utilization39.7 %
Supernet CIDR (All VLANs)23 bits
Subnet Mask255.255.255.128
Wildcard Mask0.0.0.127
How to Use This Calculator
- Enter Total Devices, Number of VLANs, and Growth Margin.
- Set Second Octet (10.X.0.0).
- Review Subnet CIDR (bits), Hosts per Subnet, and Total Usable IPs.
- Use Devices per VLAN and Devices + Growth to inform your decision.
- Use the chart to visualize the results and explore different scenarios by adjusting inputs.
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Formula
Hosts = 2^(32-CIDR) - 2; CIDR = smallest where Hosts ≥ Devices × (1+Growth)Related Calculators
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