Subnet Calculator
Visualise subnet masks in binary, calculate host ranges, and explore private IP space.
Private & Reserved IP Ranges
| Name | CIDR | Range | Addresses | Purpose |
|---|---|---|---|---|
| Class A Private | 10.0.0.0/8 | 10.0.0.0 – 10.255.255.255 | 16,777,216 | Large private networks (RFC 1918) |
| Class B Private | 172.16.0.0/12 | 172.16.0.0 – 172.31.255.255 | 1,048,576 | Medium private networks (RFC 1918) |
| Class C Private | 192.168.0.0/16 | 192.168.0.0 – 192.168.255.255 | 65,536 | Home & small office (RFC 1918) |
| Loopback | 127.0.0.0/8 | 127.0.0.0 – 127.255.255.255 | 16,777,216 | Local host (127.0.0.1 = localhost) |
| Link-Local / APIPA | 169.254.0.0/16 | 169.254.0.0 – 169.254.255.255 | 65,536 | Auto-assigned when DHCP fails |
| Shared Address Space | 100.64.0.0/10 | 100.64.0.0 – 100.127.255.255 | 4,194,304 | ISP carrier-grade NAT (RFC 6598) |
| Multicast | 224.0.0.0/4 | 224.0.0.0 – 239.255.255.255 | 268,435,456 | One-to-many routing |
| Documentation | 192.0.2.0/24 | 192.0.2.0 – 192.0.2.255 | 256 | Examples & docs (TEST-NET-1, RFC 5737) |
Inputs
Binary Visualisation
| IP | ||||||||
| Mask | ||||||||
| Network | ||||||||
| Broadcast | ||||||||
Enter a Gateway IP above to see the binary representation.