CIDR prefix
/16
255.255.0.0
65,534 usable hosts · 65,536 addresses
The mask for /16 is 255.255.0.0 — 65,536 addresses, 65,534 usable hosts. A classic Class B block (e.g. 192.168.0.0/16 — the RFC 1918 private range).
Mask
255.255.0.0
Wildcard
0.0.255.255
Addresses
65,536
Hosts
65,534
Worked example: 192.168.0.0/16
Network address192.168.0.0/16
Broadcast address192.168.255.255
First host192.168.0.1
Last host192.168.255.254
FAQ — /16
What is the subnet mask for /16?
The subnet mask for /16 is 255.255.0.0 (wildcard: 0.0.255.255). The first 16 bits are the network part, the remaining 16 are the host part.
How many hosts fit in a /16?
A /16 block holds 65,536 addresses, of which 65,534 are usable hosts (the network and broadcast addresses are excluded).
How many /16 subnets fit in a /8?
A /8 network divides into 256 /16 subnets.
What is a /16 used for?
A classic Class B block (e.g. 192.168.0.0/16 — the RFC 1918 private range).