Enter a CIDR block and instantly see the network address, broadcast, usable host range, subnet mask, and binary breakdown.
| CIDR | Subnet Mask | Addresses | Usable Hosts |
|---|---|---|---|
| /32 | 255.255.255.255 | 1 | 1 |
| /30 | 255.255.255.252 | 4 | 2 |
| /28 | 255.255.255.240 | 16 | 14 |
| /27 | 255.255.255.224 | 32 | 30 |
| /26 | 255.255.255.192 | 64 | 62 |
| /25 | 255.255.255.128 | 128 | 126 |
| /24 | 255.255.255.0 | 256 | 254 |
| /20 | 255.255.240.0 | 4,096 | 4,094 |
| /16 | 255.255.0.0 | 65,536 | 65,534 |
| /12 | 255.240.0.0 | 1,048,576 | 1,048,574 |
| /8 | 255.0.0.0 | 16,777,216 | 16,777,214 |
See network and host bits highlighted in the binary view. Understand exactly where the subnet boundary is.
Drag the prefix slider to quickly explore different subnet sizes. See hosts and ranges update in real time.
Network, broadcast, first/last host, subnet mask, wildcard mask, total addresses, and usable hosts — all at once.
See the IP, mask, network, and broadcast in binary with network bits highlighted in green and host bits in amber.
Common subnets including private ranges, Docker defaults, and point-to-point links. One click to explore.
All calculations run in your browser. Works offline. No data sent anywhere.