Subnet Calculator
Network, broadcast, host range and mask for any IPv4 subnet — plus a VLSM planner.
Calculate a subnet
Type 192.168.1.10/24, 192.168.1.10 255.255.255.0, or an address and pick a prefix.
- Network address
- 192.168.1.0
- Broadcast address
- 192.168.1.255
- First usable host
- 192.168.1.1
- Last usable host
- 192.168.1.254
- Usable hosts
- 254
- Total addresses
- 256
- Subnet mask
- 255.255.255.0
- Wildcard mask
- 0.0.0.255
- CIDR
- 192.168.1.0/24
- Block size
- 256 in the 4th octet
- IP class
- C
- Address type
- Private (RFC 1918)
In binary
Network bits · Host bits — the | marks where the /24 prefix ends.
Address
11000000.10101000.00000001.00001010Mask
11111111.11111111.11111111.00000000Network
11000000.10101000.00000001.00000000VLSM planner
Split one network into subnets of different sizes. Largest first, each gets the smallest block that fits its hosts plus the network and broadcast addresses.
| Subnet | Hosts needed | Network | Mask | Usable range | Broadcast | Spare |
|---|---|---|---|---|---|---|
| Sales | 100 | 192.168.10.0/25 | 255.255.255.128 | 192.168.10.1 – 192.168.10.126 | 192.168.10.127 | 26 |
| Engineering | 50 | 192.168.10.128/26 | 255.255.255.192 | 192.168.10.129 – 192.168.10.190 | 192.168.10.191 | 12 |
| HR | 20 | 192.168.10.192/27 | 255.255.255.224 | 192.168.10.193 – 192.168.10.222 | 192.168.10.223 | 10 |
| WAN link | 2 | 192.168.10.224/30 | 255.255.255.252 | 192.168.10.225 – 192.168.10.226 | 192.168.10.227 | 0 |
28 addresses left, starting at 192.168.10.228.