IP Subnet Calculator: CIDR

The subnet calculator network engineers actually keep on their phone.

Type any IPv4 address, slide the CIDR — get the network, broadcast, mask, wildcard, host range, total/usable hosts, IP class, and binary breakdown instantly. No login. No internet. No tracking.

WHY ENGINEERS PICK THIS ONE:

🔢 IPv4 + CIDR (0–32)
Smooth slider lets you scan the entire prefix space. Network and host bits highlight live in the binary view.

⚡ Instant Subnet Results
Network Address · Broadcast · Subnet Mask · Wildcard Mask · First Host · Last Host · Total Hosts · Usable Hosts. Tap any value to copy.

🟦 Binary Visualization
Each octet shown as 8-bit binary with network bits highlighted in your accent color. Hex per octet too. Finally see what /27 actually looks like.

🏷 IP Class & Private Detection
Class A/B/C/D/E auto-detected. RFC 1918 private ranges (10/8, 172.16/12, 192.168/16) flagged with a lock badge.

🎯 One-Tap Presets
192.168.1.0/24 · 10.0.0.0/8 · 172.16.0.0/12 · 127.0.0.1/32. Skip the typing for everyday subnets.

🌙 Material 3 Dark Theme
Designed to stay out of your way on long lab sessions. Light theme included.

🌍 37 Languages
English, Korean, Japanese, Spanish, Portuguese, French, German, Italian, Russian, Turkish, Polish, Dutch, Hindi, Indonesian, Vietnamese, Thai, Filipino, Arabic, Chinese (Simplified & Traditional).

PERFECT FOR:
• Network engineers and sysadmins
• CCNA / Network+ / CCNP exam prep
• DevOps and SRE on-call work
• Computer Science students
• Home lab and homelab tinkerers
• Cloud / VPC subnet planning

100% offline. Pure bit math. No data leaves your device.

Built for people who plan subnets in their head and only need the calculator to double-check.