IPv4 Subnet Calculator
Network address, broadcast, host range, wildcard mask and binary breakdown for any IPv4 CIDR block.
Results for 128.0.0.0/1
128.0.0.0/1 is the network in CIDR notation · Public
- Network address
- 128.0.0.0
- Broadcast address
- 255.255.255.255
- Subnet mask
- 128.0.0.0
- Wildcard mask
- 127.255.255.255
- Total addresses
- 2,147,483,648
- Usable hosts
- 2,147,483,646 (excludes network & broadcast)
- First usable host
- 128.0.0.1
- Last usable host
- 255.255.255.254
- CIDR notation
- 128.0.0.0/1
- IP type
- Public
How the bits line up
| Octets (binary) | ||||
|---|---|---|---|---|
| IP address | 10000000 | 00000000 | 00000000 | 00000000 |
| Subnet mask | 10000000 | 00000000 | 00000000 | 00000000 |
| Network | 10000000 | 00000000 | 00000000 | 00000000 |
| Broadcast | 11111111 | 11111111 | 11111111 | 11111111 |
The mask's 1 leading ones select the network portion; the remaining 31 bits are available for hosts.
Keep exploring
See every fact about the /1 subnet mask, plan multiple subnets with the VLSM calculator, or convert ranges on the range-to-CIDR tool.