IP Subnet Calculator — CIDR → Mask, Range & Hosts

Network homework or office VLAN planning: one input gives the full subnet breakdown, instantly.

Quick answer: Free subnet calculator: enter IP/CIDR (e.g. 192.168.1.0/26) — get mask, wildcard, network, broadcast, first/last host and count.

How to use

  1. Type IP + CIDR (a.b.c.d/n).
  2. Read the full breakdown live.

About this tool

Slash-notation is compact but opaque. Type 10.0.0.0/26 and instantly see /26's mask (255.255.255.192), its 64 addresses, usable hosts, network and broadcast addresses — the math network admins do daily, done honestly with real bit arithmetic.

FAQ

What does /26 mean?
26 network bits → mask 255.255.255.192 → 64 addresses (62 usable).
Why two fewer hosts?
Network and broadcast addresses are reserved — always count −2.
Private ranges?
IPv4 private: 10/8, 172.16/12, 192.168/16 — plan inside them.
IPv6?
This tool is IPv4 (the common subnetting need); IPv6 subnets are usually just prefix math.
Is it exact?
Yes — real 32-bit arithmetic, no approximations.
Offline?
Yes.