/12 Subnet
Subnet Mask
255.240.0.0
Wildcard Mask
0.15.255.255
Total IPs
1,048,576
Usable Hosts
1,048,574
Network Bits
12
Host Bits
20
About /12 Networks
Class B aggregate — large campus or regional network. A /12 subnet uses the mask 255.240.0.0 and provides 1,048,574 usable host addresses out of 1,048,576 total IPs.
Example /12 Networks
| Network | Broadcast | First Host | Last Host |
|---|---|---|---|
| 10.0.0.0/12 | 10.15.255.255 | 10.0.0.1 | 10.15.255.254 |
| 172.16.0.0/12 | 172.31.255.255 | 172.16.0.1 | 172.31.255.254 |
| 192.160.0.0/12 | 192.175.255.255 | 192.160.0.1 | 192.175.255.254 |
| 192.160.0.0/12 | 192.175.255.255 | 192.160.0.1 | 192.175.255.254 |
| 8.0.0.0/12 | 8.15.255.255 | 8.0.0.1 | 8.15.255.254 |
Adjacent CIDRs
Frequently Asked Questions
What is a /12 subnet?
A /12 subnet uses the subnet mask 255.240.0.0 with 1,048,574 usable host addresses and 1,048,576 total IP addresses. It has 12 network bits and 20 host bits.
How many hosts in a /12 network?
A /12 network supports 1,048,574 usable hosts out of 1,048,576 total IP addresses. The usable range excludes the network address and broadcast address.
What subnet mask does /12 use?
A /12 subnet uses the mask 255.240.0.0 (wildcard mask 0.15.255.255). This means the first 12 bits identify the network and the remaining 20 bits identify hosts.