IP Subnet Calculator (CIDR)
Calculate IPv4 subnets online for free: network and broadcast address, usable host range, subnet mask and wildcard from any CIDR notation.
| Network address | 192.168.1.0 |
| Broadcast address | 192.168.1.255 |
| Subnet mask | 255.255.255.0 |
| Wildcard mask | 0.0.0.255 |
| First usable host | 192.168.1.1 |
| Last usable host | 192.168.1.254 |
| Usable hosts | 254 |
| CIDR notation | 192.168.1.0/24 |
Frequently asked questions
- Are my files uploaded to a server?
- No. This tool runs entirely in your browser using JavaScript — your files never leave your device.
- What does /24 mean?
- The CIDR prefix is how many leading bits form the network part. /24 means a 255.255.255.0 mask with 256 addresses, 254 of them usable hosts.
- Why are two addresses unusable?
- The first address identifies the network itself and the last is the broadcast address. /31 point-to-point links (RFC 3021) and /32 single hosts are the exceptions, which this tool handles.