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IP / CIDR Calculator

Calculate network address, broadcast address, host range, subnet mask, and usable host count from any IPv4 CIDR notation — instant, browser-based.

100% client-side · no upload

How to use

  1. Type your network in CIDR notation, such as 10.0.0.0/8 or 172.16.0.0/12.
  2. Click Calculate to compute the full subnet details.
  3. Copy the network address, broadcast, or host range for use in firewall rules, routing configs, or documentation.

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Frequently Asked Questions

Is this IP/CIDR calculator free?
Yes, completely free with no signup and no usage limits.
Does my data leave my device?
No. All calculations run in JavaScript inside your browser. Nothing is sent to any server.
Does it work on mobile?
Yes. The tool is mobile-first and works on iPhone Safari and Android Chrome.

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