Features
Subnet Mask
Instantly computes the dotted-decimal subnet mask from any CIDR notation.
Number of Hosts
Calculates the total usable host addresses for any subnet size.
Broadcast Address
Finds the broadcast address for any IP and subnet combination.
Wildcard Mask
Displays the wildcard (inverse) mask used in ACLs and routing protocols.
Host Range
Shows the first and last usable IP addresses in the subnet.
Binary View
See the netmask in binary format for educational purposes.
Simple. Fast. Offline.
Adjust the IP octets and CIDR prefix with native number pickers — results update instantly. No internet required.
Open Source
Licensed under the BSD 2-Clause license. Contributions welcome on GitHub.
View on GitHub