IPv4/IPv6 Subnet Calculator
How to Calculate IPv4 and IPv6 Subnets Locally on your Mac
Subnet math should not require a network call. CodeSwissKnife calculates IPv4 and IPv6 ranges, masks, prefixes and exact address counts locally from the addresses you type.
Why calculate subnets locally?
Network ranges can describe internal infrastructure. Local calculation keeps address planning and debugging work on your Mac.
Handle IPv4 and IPv6 edge cases
The calculator covers /31, /32 and /0 behavior for IPv4, dotted masks, IPv6 exact address counts and how many /64 links fit inside a prefix.
Check containment and ranges
Use a second address to answer whether it belongs inside a subnet, while strict parsing avoids ambiguous input such as unsafe octal-looking IPv4 values.
Use IPv4/IPv6 Subnet Calculator on macOS
Download CodeSwissKnife to keep this network workflow and the rest of your developer tools in one native Mac app.