Subnet / CIDR Calculator
Calculates subnet mask, wildcard mask, host ranges, and binary layout. Includes a VLSM planner for designing variable-length subnet schemes.
Enter an IP with prefix length, e.g. 10.0.0.0/8 or 172.16.50.1/22. Host bits are zeroed to the network address.
Subnet Information
Binary Representation
network hostDivide into Equal Subnets
Split at prefix
/
| # | Network | First Host | Last Host | Hosts |
|---|
VLSM Planner
Variable Length Subnet Masking — requirements sorted largest-first for optimal packing
| Name | Hosts Needed | Prefix | Network | Usable | |||
|---|---|---|---|---|---|---|---|
Click Add Subnet to start planning your VLSM allocation.