Enter a valid CIDR string to see network metrics.
IP / CIDR Calculator (Offline & Secure)
Free online CIDR calculator — parse IPv4 CIDR blocks to get network address, broadcast, wildcard mask, and usable host range. Runs in your browser.
How to use CIDR Calculator
- Type a valid IPv4 CIDR notation (e.g. 192.168.1.0/24) into the input field.
- View the calculated Network Address, Broadcast Address, Wildcard Mask, and Host Range.
Edge Cases & Important Considerations
- Only IPv4 addresses are currently supported.
- /31 and /32 prefixes are handled according to special point-to-point and host route rules.
Keyboard Shortcuts
- Ctrl/Cmd + K — Open Command Palette to switch tools instantly.
Frequently Asked Questions
Is this CIDR Calculator safe for sensitive corporate data?
Yes, 100%. All processing runs client-side in your local browser memory. No text, tokens, payloads, or logs are ever transmitted to any remote server or analytics engine.
Can I use this tool offline?
Yes. Because this tool runs strictly on client-side JavaScript with zero external API dependencies, once loaded it functions completely offline.
100% Client-Side Privacy Guarantee
All inputs are processed entirely inside your browser's memory using JavaScript. No data is ever transmitted to any server. Your tokens, JSON payloads, cURL commands, and timestamps never leave your machine.