Subnet Calculator
Enter an IPv4 CIDR to calculate network address, broadcast, mask and usable host range.
Enter a value above and run the check to see results here.
How it works
Enter an IPv4 CIDR to calculate network address, broadcast, mask and usable host range.
This tool runs entirely in your browser — your input never leaves your device.
Frequently asked questions
Is the Subnet Calculator tool free to use?+
Yes. The Subnet Calculator runs directly in NetInsight with no signup required. Free-tier usage is rate limited to keep the service fast for everyone.
Are my queries logged?+
Diagnostic inputs are processed to produce your result and are not sold or shared. See our Privacy Policy for full detail on retention.
How accurate are the Subnet Calculator results?+
Results are fetched live from authoritative sources each time you run a check, so they reflect the current state rather than a cached snapshot.