Tools
Subnet Calculator
Enter an IPv4 address with a CIDR prefix or subnet mask. Get network address, broadcast, host range, wildcard mask, and binary breakdown — instantly, in your browser.
Quick load:
Network address
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Broadcast address
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First usable host
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Last usable host
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Usable hosts
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Subnet mask
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Wildcard mask
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CIDR notation
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Binary breakdown
| Field | Octet 1 | Octet 2 | Octet 3 | Octet 4 |
|---|
Common subnet reference — click any row to calculate
| CIDR | Subnet mask | Wildcard | Hosts | Typical use |
|---|---|---|---|---|
| /8 | 255.0.0.0 | 0.255.255.255 | 16,777,214 | Class A (10.x.x.x) |
| /12 | 255.240.0.0 | 0.15.255.255 | 1,048,574 | 172.16.0.0 private block |
| /16 | 255.255.0.0 | 0.0.255.255 | 65,534 | Class B / large campus |
| /20 | 255.255.240.0 | 0.0.15.255 | 4,094 | Medium campus VLAN |
| /22 | 255.255.252.0 | 0.0.3.255 | 1,022 | Large office floor |
| /23 | 255.255.254.0 | 0.0.1.255 | 510 | Office floor |
| /24 | 255.255.255.0 | 0.0.0.255 | 254 | Standard LAN / VLAN |
| /25 | 255.255.255.128 | 0.0.0.127 | 126 | Split LAN |
| /26 | 255.255.255.192 | 0.0.0.63 | 62 | Small VLAN |
| /27 | 255.255.255.224 | 0.0.0.31 | 30 | Small segment |
| /28 | 255.255.255.240 | 0.0.0.15 | 14 | Server cluster |
| /29 | 255.255.255.248 | 0.0.0.7 | 6 | Small cluster |
| /30 | 255.255.255.252 | 0.0.0.3 | 2 | Point-to-point link |
| /31 | 255.255.255.254 | 0.0.0.1 | 2* | P2P (RFC 3021) |
| /32 | 255.255.255.255 | 0.0.0.0 | 1 | Host route |
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