Subnet Calculator
Calculate network address, broadcast, usable host range, wildcard mask, and host count from any IPv4 address and CIDR prefix.
Your details
This calculator runs entirely on your device. Nothing you enter is uploaded, stored, or sold. How this works
Network
192.168.1.0/24
254 usable hosts — 192.168.1.1 to 192.168.1.254
Includes your inputs, the full breakdown, and every row of the table.
Subnet mask
255.255.255.0
Broadcast address
192.168.1.255
Usable hosts
254
Address type
Private (RFC 1918)
- IP address
- 192.168.1.130
- CIDR notation
- 192.168.1.0/24
- Subnet mask
- 255.255.255.0
- Wildcard mask
- 0.0.0.255
- Network address
- 192.168.1.0
- First usable host
- 192.168.1.1
- Last usable host
- 192.168.1.254
- Broadcast address
- 192.168.1.255
- Total addresses
- 256
- Usable addresses
- 254
- IP in binary
- 11000000.10101000.00000001.10000010
- Mask in binary
- 11111111.11111111.11111111.00000000
- Integer value
- 3,232,235,906
| CIDR | Subnet mask | Total addresses | Usable hosts |
|---|---|---|---|
| /30 | 255.255.255.252 | 4 | 2 |
| /29 | 255.255.255.248 | 8 | 6 |
| /28 | 255.255.255.240 | 16 | 14 |
| /27 | 255.255.255.224 | 32 | 30 |
| /26 | 255.255.255.192 | 64 | 62 |
| /25 | 255.255.255.128 | 128 | 126 |
| /24 | 255.255.255.0 | 256 | 254 |
What this means
- Two addresses in every subnet are reserved: the network address and the broadcast address. They cannot be assigned to hosts.
- This is a private address from RFC 1918 space and is not routable on the public internet.
How the subnet calculation works
A subnet mask splits an IPv4 address into a network portion and a host portion. The CIDR prefix is simply the count of leading one-bits in the mask, so /24 means the first 24 bits identify the network and the remaining 8 bits identify hosts within it.
Everything else falls out of that split. The network address is the IP bitwise-ANDed with the mask, the broadcast is the network with all host bits set to one, and the usable range is everything between them. Usable host count is 2^(32−prefix) minus the two reserved addresses.
Frequently asked questions
How many hosts are in a /24?
256 total addresses, 254 usable. The network address (.0) and broadcast address (.255) are reserved.
What is a wildcard mask?
The bitwise inverse of the subnet mask. Cisco ACLs and OSPF configurations use wildcard masks rather than subnet masks — /24 becomes 0.0.0.255.
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Disclaimer. This calculator is provided for general information and educational purposes only and does not constitute financial, tax, legal, medical, or engineering advice. Results are estimates based on the inputs you provide and the assumptions described above. Confirm any figure with a qualified professional before acting on it.