/16 subnet

Mask 255.255.0.0 · 65,534 usable hosts · 65,536 addresses

/16 at a glance
Subnet mask255.255.0.0
Wildcard mask0.0.255.255
Binary mask11111111.11111111.00000000.00000000
Network / host bits16 / 16
Total addresses65,536
Usable hosts65,534
Per /8 · /16 · /24256 · 1 · –
Example192.168.10.77/16 → network 192.168.0.0, hosts 192.168.0.1 – 192.168.255.254, broadcast 192.168.255.255

Where /16 is used

The 192.168.0.0/16 private range; a typical AWS VPC.

Block boundaries: a /16 must start at a multiple of 65,536 addresses. Calculate any specific address in the subnet calculator.

Neighbouring prefixes

← /15 (twice as large) · /17 (half the size) →

Questions

How many hosts in a /16?
65,536 addresses, of which 65,534 are usable (the first is the network address and the last is broadcast).
What is the subnet mask for /16?
255.255.0.0. In binary: 11111111.11111111.00000000.00000000. The wildcard (inverse) mask is 0.0.255.255.