/27 Subnet
30 usable hosts — small workgroup
A /27 provides 32 addresses with 30 usable hosts. Suitable for small workgroups, point-of-presence (PoP) subnets, or management networks where only a handful of devices are present.
Common Use Cases
- → Small workgroup LAN
- → Network device management subnet
- → Cloud NAT gateway subnet
- → Transit subnet
Example /27 Networks
| CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|
| 10.0.0.0/27 | 10.0.0.0 | 10.0.0.1 | 10.0.0.30 | 10.0.0.31 | 30 |
| 172.16.0.0/27 | 172.16.0.0 | 172.16.0.1 | 172.16.0.30 | 172.16.0.31 | 30 |
| 172.31.0.0/27 | 172.31.0.0 | 172.31.0.1 | 172.31.0.30 | 172.31.0.31 | 30 |
| 192.168.0.0/27 | 192.168.0.0 | 192.168.0.1 | 192.168.0.30 | 192.168.0.31 | 30 |
| 192.168.1.0/27 | 192.168.1.0 | 192.168.1.1 | 192.168.1.30 | 192.168.1.31 | 30 |
| 10.0.1.0/27 | 10.0.1.0 | 10.0.1.1 | 10.0.1.30 | 10.0.1.31 | 30 |
How /27 Compares
| Prefix | Total IPs | Usable Hosts | Subnet Mask | Typical Use |
|---|---|---|---|---|
| /24 | 256 | 254 | 255.255.255.0 | Standard subnet — home, office, cloud |
| /25 | 128 | 126 | 255.255.255.128 | Half a /24 — public/private split |
| /26 | 64 | 62 | 255.255.255.192 | Cloud per-tier subnet, small VLAN |
| /27 ◀ | 32 | 30 | 255.255.255.224 | Small workgroup / management subnet |
| /28 | 16 | 14 | 255.255.255.240 | AWS NAT/endpoint dedicated subnet |
| /29 | 8 | 6 | 255.255.255.248 | Tiny server cluster or infra segment |
| /30 | 4 | 2 | 255.255.255.252 | WAN point-to-point link |
Frequently Asked Questions
How many IPs are in a /27?
A /27 subnet contains 32 total IP addresses and 30 usable host addresses. The network address (first IP) and broadcast address (last IP) are reserved and cannot be assigned to hosts.
What is the subnet mask for /27?
The subnet mask for a /27 is 255.255.255.224.
In CIDR notation, the prefix length /27 means
the first 27 bits of the address are the network portion.
The wildcard (inverse) mask is 0.0.0.31.
How many /27 subnets fit in a /26?
Exactly 2 — a /26 can be split into two /27 subnets of equal size. Each /27 subnet has 30 usable hosts, compared to 62 in the parent /26.