CIDR prefix
/18
255.255.192.0
16,382 usable hosts · 16,384 addresses
The mask for /18 is 255.255.192.0 — 16,384 addresses, 16,382 usable hosts. Campus and larger office networks; /22–/23 are common for offices with a few hundred devices.
Mask
255.255.192.0
Wildcard
0.0.63.255
Addresses
16,384
Hosts
16,382
Worked example: 192.168.0.0/18
Network address192.168.0.0/18
Broadcast address192.168.63.255
First host192.168.0.1
Last host192.168.63.254
FAQ — /18
What is the subnet mask for /18?
The subnet mask for /18 is 255.255.192.0 (wildcard: 0.0.63.255). The first 18 bits are the network part, the remaining 14 are the host part.
How many hosts fit in a /18?
A /18 block holds 16,384 addresses, of which 16,382 are usable hosts (the network and broadcast addresses are excluded).
How many /18 subnets fit in a /16?
A /16 network divides into 4 /18 subnets.
What is a /18 used for?
Campus and larger office networks; /22–/23 are common for offices with a few hundred devices.