Network tools
IPv4 subnet calculator
Inspect IPv4 CIDR details or generate a VLSM allocation plan from prefix and host requirements.
VLSM allocation plan
Fixed CIDRs are reserved first. Automatic blocks follow the selected allocation order.
Subnet requirements
Examples: 3x/24, 2x/27 or Web: 2x50 hosts
Allocation plan
172.16.0.0/16
960 of 65,536 addresses1.46% allocated
7 allocations. Names and CIDRs stay editable; open a row for range, mask, capacity, and notes.
| Name | CIDR | Usable range | Mask | Capacity | Notes |
|---|---|---|---|---|---|
| 172.16.0.1254 | 255.255.255.0 | 254 hosts256 addresses | |||
| 172.16.1.1254 | 255.255.255.0 | 254 hosts256 addresses | |||
| 172.16.2.1254 | 255.255.255.0 | 254 hosts256 addresses | |||
| 172.16.3.162 | 255.255.255.192 | 62 hosts64 addresses | |||
| 172.16.3.65126 | 255.255.255.192 | 62 hosts64 addresses | |||
| 172.16.3.129158 | 255.255.255.224 | 30 hosts32 addresses | |||
| 172.16.3.161190 | 255.255.255.224 | 30 hosts32 addresses |
Remaining space · 64,576 addresses
172.16.3.192/26172.16.4.0/22172.16.8.0/21172.16.16.0/20172.16.32.0/19172.16.64.0/18172.16.128.0/17