IP Subnet Calculator
Enter an IPv4 address with CIDR notation to see its network range, mask and usable hosts.
Enter an IPv4 address in CIDR notation (like 192.168.1.0/24) and instantly get the network address, broadcast address, subnet mask, wildcard mask, and the number of usable host addresses. Built for network engineers and sysadmins planning VLANs, firewall rules, or DHCP scopes who need accurate subnet math without pulling out a calculator or cheat sheet. All computation happens locally in your browser.
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Details
- Category
- Developer & data
- Runs
- In your browser
- Files uploaded
- No
- Cost per run
- Free
- Sign-in
- Not required
- Works offline
- Yes, once loaded
Last updated 2026-08-03
Common questions
Does this do IP geolocation lookup?
No - this is a subnet/CIDR calculator only. It computes network math locally; it doesn't look up who owns an IP or where it's located.
What's the difference between network and broadcast address?
The network address identifies the subnet itself (all host bits zero); the broadcast address reaches every host on it (all host bits one). Neither is usable for a device.
How is usable host count calculated?
It's the total addresses in the subnet minus the network and broadcast addresses, except for /31 and /32 which use special rules.
Does it support IPv6?
This calculator is built for IPv4 CIDR notation.