IP/CIDR Calculator — Subnet, Network, Broadcast & Host Range Instantly

#javascript #networking #tools #webdev

IP/CIDR Calculator

I just added an IP/CIDR Calculator to devnestio — a free, browser-only subnet calculator for IPv4.

🔗 Try it → ip-cidr-calc.pages.dev

What it calculates

Enter any IP address with CIDR prefix (e.g. 192.168.1.0/24) and get:

Field	Example
Network address	192.168.1.0
Broadcast address	192.168.1.255
Subnet mask	255.255.255.0
Wildcard mask	0.0.0.255
First usable host	192.168.1.1
Last usable host	192.168.1.254
Total IPs	256
Usable hosts	254
IP class	Class C
Binary representation	dotted binary

Handles all prefix lengths

/0 — the entire internet
/8, /16, /24 — classful boundaries
/30 — typical point-to-point links (2 usable hosts)
/31 — RFC 3021 point-to-point (no network/broadcast)
/32 — single host

Quick examples

10.0.0.0/8        → Class A, 16,777,214 usable hosts
172.16.0.0/12     → Class B, 1,048,574 usable hosts
192.168.1.0/24    → Class C, 254 usable hosts
192.168.1.128/25  → /25 subnet, 126 usable hosts