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. Use the subnet calculation tool to confirm your subnet design before configuring routers, firewalls, or access control lists.
Subnet Mask Reference Table
| CIDR | Subnet Mask | Wildcard Mask | Total IPs | Usable Hosts |
|---|
Related Network Tools
Explore these related tools for subnet calculation and IP address management.
Additional networking calculators for IP address planning and network analysis. Use the cidr calculator to verify that two CIDR blocks do not overlap before adding them to a routing table.
More tools to support network design, addressing, and subnet troubleshooting. The ip binary converter converts any dotted-decimal IPv4 address to its binary equivalent — one octet at a time.
Comments & Feedback
Share your experience or ask questions about this tool