/12 Subnet Mask (255.240.0.0)
| Prefix | /12 |
|---|---|
| Subnet mask | 255.240.0.0 |
| Wildcard mask | 0.15.255.255 |
| Binary mask | 11111111.11110000.00000000.00000000 |
| Total addresses | 1,048,576 |
| Usable hosts | 1,048,574 |
| Host bits | 20 |
| Subnets of /12 in a /8 | 16 |
e.g. 10.0.0.5/22 or 10.0.0.5 255.255.252.0
| Network address | 10.0.0.0 | |
|---|---|---|
| Broadcast address | 10.15.255.255 | |
| First usable host | 10.0.0.1 | |
| Last usable host | 10.15.255.254 | |
| Total addresses | 1,048,576 | |
| Usable hosts | 1,048,574 | |
| Subnet mask | 255.240.0.0 | |
| Wildcard mask | 0.15.255.255 | |
| CIDR notation | 10.0.0.0/12 | |
| IP class | Class A (legacy) | |
| Address type | Private (RFC 1918) | |
| IP address (binary) | 00001010.00000000.00000000.00000000 | |
| Subnet mask (binary) | 11111111.11110000.00000000.00000000 |
■ network bits ■ host bits
| Requested hosts | CIDR | First host | Last host | Broadcast | Usable hosts |
|---|
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What is a /12 subnet?
A /12 subnet uses the first 12 bits of an IPv4 address for the network and leaves 20 bits for hosts. Its subnet mask is 255.240.0.0, and it contains 2²⁰ = 1,048,576 addresses, of which 1,048,574 can be assigned to devices. Typical use: 172.16.0.0/12 is the private range covering 172.16.0.0–172.31.255.255. Use the subnet calculator above to check any /12 network.
/12 subnet example
For 10.0.0.0/12: network address 10.0.0.0, usable hosts 10.0.0.1 – 10.15.255.254, broadcast address 10.15.255.255, wildcard mask 0.15.255.255.
Frequently asked questions
How many usable IPs are in a /12?
1,048,574. The block has 1,048,576 addresses; the first is the network address and the last is the broadcast address.
What is the subnet mask for /12?
255.240.0.0, or 11111111.11110000.00000000.00000000 in binary.
How many /12 subnets are in a /8?
16 (2⁴), because a /12 uses 4 more network bits than a /8.
What is the difference between /12 and /11?
A /11 (255.224.0.0) is twice as large: 2,097,152 addresses and 2,097,150 usable hosts, spanning two consecutive /12 blocks such as 10.0.0.0–10.31.255.255.