Subnet Ninja is an offline subnet calculator for network engineers and students.
IPv4
• Network, broadcast, host range, usable hosts, CIDR, and binary
• VLSM planning from host-count requirements
• Wildcard masks and special-range identification
IPv6
• Expand, compress, and work with prefixes
• /64 breakdown plus link-local, ULA, and global classification
• EUI-64 from a MAC address
ROUTES
• Aggregate prefixes to a minimal covering set
PRO
• Plain-English explainers for verified results
• Config snippet templates for common CLI setups
The calculator runs on-device. No account required.