Subnet Calculator
Enter CIDR notation (e.g. 192.168.1.0/24) and get the network address, netmask, broadcast, first/last host and usable host count. Runs in your browser.
Runs in your browser — your file never leaves your deviceFrequently asked questions
Is Subnet Calculator free to use?
Yes — Subnet Calculator is completely free with no limits, no watermarks and no sign-up. It runs in your browser, so there is nothing to pay for.
Are my files uploaded or stored anywhere?
No. This tool does all its work locally in your browser using your own device's power. Your files never leave your device and we never see them.
Do I need to install anything or create an account?
No installation and no account needed. Subnet Calculator works on any modern browser — Windows, Mac, Linux, Android and iPhone.
How do I use Subnet Calculator?
Open the tool, add your file (or paste your content), adjust any options, then press “Calculate subnet”. Your result is ready to download in seconds.