/28 subnet
Mask 255.255.255.240 · 14 usable hosts · 16 addresses
| Subnet mask | 255.255.255.240 |
|---|---|
| Wildcard mask | 0.0.0.15 |
| Binary mask | 11111111.11111111.11111111.11110000 |
| Network / host bits | 28 / 4 |
| Total addresses | 16 |
| Usable hosts | 14 |
| Per /8 · /16 · /24 | 1,048,576 · 4,096 · 16 |
| Example | 192.168.10.77/28 → network 192.168.10.64, hosts 192.168.10.65 – 192.168.10.78, broadcast 192.168.10.79 |
Where /28 is used
Very small segments, DMZs, small public IP allocations from ISPs.
Block boundaries: a /28 must start at a multiple of 16 addresses, so in the last octet networks start at 0, 16, 32, 48, 64, 80, 96, 112…. Calculate any specific address in the subnet calculator.
Neighbouring prefixes
Questions
How many hosts in a /28?
16 addresses, of which 14 are usable (the first is the network address and the last is broadcast).
What is the subnet mask for /28?
255.255.255.240. In binary: 11111111.11111111.11111111.11110000. The wildcard (inverse) mask is 0.0.0.15.