Enter an IPv4 address and CIDR prefix to see subnet details.
| CIDR | Subnet Mask | Total IPs | Usable Hosts | Typical Use |
|---|---|---|---|---|
| /30 | 255.255.255.252 | 4 | 2 | Point-to-point links |
| /28 | 255.255.255.240 | 16 | 14 | Small office |
| /24 | 255.255.255.0 | 256 | 254 | Standard LAN |
| /20 | 255.255.240.0 | 4,096 | 4,094 | Medium campus |
| /16 | 255.255.0.0 | 65,536 | 65,534 | Large enterprise |
| /8 | 255.0.0.0 | 16,777,216 | 16,777,214 | Class A network |
It separates the network portion from the host portion of an IP address. /24 means first 24 bits = network, last 8 bits = hosts.
Classless Inter-Domain Routing. /24 replaces the old Class C label. Allows flexible subnet sizes.
First = network address, last = broadcast address. Neither is assignable to a device.