Kernaali ToolsHow it works
An IPv4 address has 32 bits. A /p prefix leaves 32 − p host bits, so its block contains 2^(32 − p) addresses. Clear the host bits to find the network; set them to find the final address. Ordinary subnets reserve the network and broadcast addresses.
Worked example
10.42.7.93/26 falls inside 10.42.7.64/26. The final address is 10.42.7.127, leaving 10.42.7.65–10.42.7.126 for 62 ordinary hosts.
Inputs, edge cases & common mistakes
Enter four decimal octets followed by /0 through /32. Surrounding whitespace is accepted; ambiguous leading-zero octets are rejected. /31 uses the RFC 3021 point-to-point interpretation with two endpoints. /32 describes one host. A /0 count is arithmetic, not a claim that every address is assignable. Check the special-address reference before using a range.
Technical references
Reviewed 9 September 2026. Found an issue? Send a correction with a reproducible example.