Calculate IPv4 subnet details including network address, broadcast address, usable host range, and wildcard mask from any IP and CIDR notation.
Subnetting divides a larger network into smaller, more manageable sub-networks (subnets). This improves network performance, security, and IP address management. The subnet mask determines which portion of an IP address identifies the network and which identifies the host.
CIDR (Classless Inter-Domain Routing) notation uses a slash followed by the number of network bits. For example, /24 means the first 24 bits are the network portion, leaving 8 bits for host addresses (256 total, 254 usable).
| CIDR | Subnet Mask | Usable Hosts | Total IPs |
|---|---|---|---|
| /8 | 255.0.0.0 | 16,777,214 | 16,777,216 |
| /16 | 255.255.0.0 | 65,534 | 65,536 |
| /24 | 255.255.255.0 | 254 | 256 |
| /28 | 255.255.255.240 | 14 | 16 |
| /30 | 255.255.255.252 | 2 | 4 |
| /32 | 255.255.255.255 | 1 | 1 |
Two addresses are reserved: the first (network address, e.g., 192.168.1.0) identifies the network itself, and the last (broadcast address, e.g., 192.168.1.255) is used to send data to all hosts on the subnet.