/25 Subnet
Subnet Mask
255.255.255.128
Wildcard Mask
0.0.0.127
Total IPs
128
Usable Hosts
126
Network Bits
25
Host Bits
7
About /25 Networks
Half of a /24 — used when a full /24 is too large (126 hosts). A /25 subnet uses the mask 255.255.255.128 and provides 126 usable host addresses out of 128 total IPs.
Example /25 Networks
| Network | Broadcast | First Host | Last Host |
|---|---|---|---|
| 10.0.0.0/25 | 10.0.0.127 | 10.0.0.1 | 10.0.0.126 |
| 172.16.0.0/25 | 172.16.0.127 | 172.16.0.1 | 172.16.0.126 |
| 192.168.0.0/25 | 192.168.0.127 | 192.168.0.1 | 192.168.0.126 |
| 192.168.1.0/25 | 192.168.1.127 | 192.168.1.1 | 192.168.1.126 |
| 8.8.8.0/25 | 8.8.8.127 | 8.8.8.1 | 8.8.8.126 |
Adjacent CIDRs
Frequently Asked Questions
What is a /25 subnet?
A /25 subnet uses the subnet mask 255.255.255.128 with 126 usable host addresses and 128 total IP addresses. It has 25 network bits and 7 host bits.
How many hosts in a /25 network?
A /25 network supports 126 usable hosts out of 128 total IP addresses. The usable range excludes the network address and broadcast address.
What subnet mask does /25 use?
A /25 subnet uses the mask 255.255.255.128 (wildcard mask 0.0.0.127). This means the first 25 bits identify the network and the remaining 7 bits identify hosts.