Subnet Calculator
Enter an IP address with CIDR notation or subnet mask to calculate the network address, broadcast address, host range, and more.
Enter as CIDR (192.168.1.0/24), IP + mask (192.168.1.0 255.255.255.0), or just an IP (defaults to /24).
Examples
Common Subnet Masks
| CIDR | Subnet Mask | Usable Hosts | Typical Use |
|---|---|---|---|
| /8 | 255.0.0.0 | 16,777,214 | Class A default |
| /12 | 255.240.0.0 | 1,048,574 | 10.x.x.x private |
| /16 | 255.255.0.0 | 65,534 | Class B default |
| /20 | 255.255.240.0 | 4,094 | Large office |
| /21 | 255.255.248.0 | 2,046 | Medium campus |
| /22 | 255.255.252.0 | 1,022 | Large subnet |
| /23 | 255.255.254.0 | 510 | Medium subnet |
| /24 | 255.255.255.0 | 254 | Class C default / typical LAN |
| /25 | 255.255.255.128 | 126 | Half Class C |
| /26 | 255.255.255.192 | 62 | Quarter Class C |
| /27 | 255.255.255.224 | 30 | Small office |
| /28 | 255.255.255.240 | 14 | Small LAN |
| /29 | 255.255.255.248 | 6 | Point-to-multipoint |
| /30 | 255.255.255.252 | 2 | Point-to-point link |
| /31 | 255.255.255.254 | 2 | P2P link (RFC 3021) |
| /32 | 255.255.255.255 | 1 | Host route / loopback |