Subnet Mask Calculator
Enter a CIDR prefix length or specify your required number of hosts to instantly calculate the correct subnet mask in dotted-decimal, binary, and hexadecimal formats. Find the optimal mask size for your network, view usable host ranges, and convert between subnet mask notations — all in one place. The free subnet calculator produces binary representations alongside decimal results so you can verify subnet calculations at the bit level.
Subnet Mask Reference Table
| CIDR | Subnet Mask | Wildcard Mask | Total IPs | Usable Hosts |
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