IPv4 Subnet Calculator
Network address, broadcast, host range, wildcard mask and binary breakdown for any IPv4 CIDR block.
Results for 198.51.104.0/21
198.51.104.0/21 is the network in CIDR notation · Public
- Network address
- 198.51.104.0
- Broadcast address
- 198.51.111.255
- Subnet mask
- 255.255.248.0
- Wildcard mask
- 0.0.7.255
- Total addresses
- 2,048
- Usable hosts
- 2,046 (excludes network & broadcast)
- First usable host
- 198.51.104.1
- Last usable host
- 198.51.111.254
- CIDR notation
- 198.51.104.0/21
- IP type
- Public
How the bits line up
| Octets (binary) | ||||
|---|---|---|---|---|
| IP address | 11000110 | 00110011 | 01101000 | 00000000 |
| Subnet mask | 11111111 | 11111111 | 11111000 | 00000000 |
| Network | 11000110 | 00110011 | 01101000 | 00000000 |
| Broadcast | 11000110 | 00110011 | 01101111 | 11111111 |
The mask's 21 leading ones select the network portion; the remaining 11 bits are available for hosts.
Keep exploring
See every fact about the /21 subnet mask, plan multiple subnets with the VLSM calculator, or convert ranges on the range-to-CIDR tool.