Calculate network ranges, host counts, broadcast addresses, and CIDR breakdowns for IPv4 and IPv6 networks.
Divide a parent network into equal-sized subnets, either by specifying how many networks you need or how many usable hosts each subnet must support. Hover over any network/CIDR value to see its subnet mask.
| # | Network | Usable Host Range | Broadcast Address | Usable Hosts |
|---|
| Class | Address Range | Default Mask | CIDR | Typical Use |
|---|---|---|---|---|
| A | 1.0.0.0 - 126.255.255.255 | 255.0.0.0 | /8 | Large networks |
| B | 128.0.0.0 - 191.255.255.255 | 255.255.0.0 | /16 | Medium networks |
| C | 192.0.0.0 - 223.255.255.255 | 255.255.255.0 | /24 | Small networks |
| D | 224.0.0.0 - 239.255.255.255 | N/A | N/A | Multicast |
| E | 240.0.0.0 - 255.255.255.255 | N/A | N/A | Experimental / reserved |
These address blocks are reserved for internal, private use and are never routed on the public Internet. Anyone can freely use them inside their own network without registration — devices using these addresses reach the internet only through NAT (Network Address Translation) at the network edge.
| Range | Address Range | Default Mask | CIDR | Typical Use |
|---|---|---|---|---|
| 10.x | 10.0.0.0 - 10.255.255.255 | 255.0.0.0 | /8 | Large private networks (RFC 1918) |
| 172.16.x | 172.16.0.0 - 172.31.255.255 | 255.240.0.0 | /12 | Medium private networks (RFC 1918) |
| 192.168.x | 192.168.0.0 - 192.168.255.255 | 255.255.0.0 | /16 | Small private networks / home routers (RFC 1918) |
| 100.64.x | 100.64.0.0 - 100.127.255.255 | 255.192.0.0 | /10 | Carrier-Grade NAT / ISP shared address space (RFC 6598) |
| 169.254.x | 169.254.0.0 - 169.254.255.255 | 255.255.0.0 | /16 | Link-local / APIPA auto-assigned addresses (RFC 3927) |
| 127.x | 127.0.0.0 - 127.255.255.255 | 255.0.0.0 | /8 | Loopback (localhost) |