/12 subnet

Mask 255.240.0.0 · 1,048,574 usable hosts · 1,048,576 addresses

/12 at a glance
Subnet mask255.240.0.0
Wildcard mask0.15.255.255
Binary mask11111111.11110000.00000000.00000000
Network / host bits12 / 20
Total addresses1,048,576
Usable hosts1,048,574
Per /8 · /16 · /2416 · – · –
Example192.168.10.77/12 → network 192.160.0.0, hosts 192.160.0.1 – 192.175.255.254, broadcast 192.175.255.255

Where /12 is used

The 172.16.0.0/12 private range.

Block boundaries: a /12 must start at a multiple of 1,048,576 addresses. Calculate any specific address in the subnet calculator.

Neighbouring prefixes

← /11 (twice as large) · /13 (half the size) →

Questions

How many hosts in a /12?
1,048,576 addresses, of which 1,048,574 are usable (the first is the network address and the last is broadcast).
What is the subnet mask for /12?
255.240.0.0. In binary: 11111111.11110000.00000000.00000000. The wildcard (inverse) mask is 0.15.255.255.