Tukuk-OS🕸️ Subnet Calculator
ℹ️ What this tool does & how it works
A prefix length is just log arithmetic: /26 means 26 mask bits, 6 host bits, a block of 2\u2076 = 64 addresses, of which the first is the network and the last the broadcast — 62 usable. Everything below comes from those numbers with integer division; no lookup tables, no "class" folklore, and nothing is sent anywhere.
Why /24 is not "254" anymore — and /26 is 62
Classful networking (the A/B/C folklore still haunting the word "class-C") died in 1993 with CIDR; what survived is the arithmetic: a prefix of p leaves 32\u2212p host bits, and usable hosts are 2^(32\u2212p) \u2212 2 because the all-zero host address names the network itself and the all-ones one is the broadcast. A /26 block is 64 addresses, 62 usable — the number that decides whether a VLAN fits its DHCP scope. The second trap this page surfaces: people paste a host address and expect a network back; 192.168.1.130/26 is not a network at all — the containing block is .128/26, and the page says so rather than pretending the input was canonical.