Detailed information about IPv4 /12 subnets
A /12 network is very large and can support thousands to millions of hosts. These are typically used by large organizations or internet service providers.
| CIDR Notation | /12 |
| Subnet Mask | 255.240.0.0 |
| Binary Subnet Mask | 11111111 11110000 00000000 00000000 |
| Total Addresses | 1,048,576 |
| Usable Hosts (Standard) | 1,048,574 |
| AWS Usable IPs | 1,048,569 |
| Azure Usable IPs | 1,048,569 |
| GCP Usable IPs | 1,048,570 |
A CIDR /12 subnet has 1,048,574 usable IP addresses for hosts. This is a relatively large subnet that can be further divided into smaller subnets if needed.
Organizations typically use subnets of this size for large-scale deployments or when planning for future growth.
Cloud providers reserve some IP addresses in each subnet for internal use, resulting in fewer usable IPs:
When planning your cloud infrastructure, consider these reserved addresses to accurately size your subnets.