IP Subnet Calculator
Enter an IPv4 address and CIDR (e.g. 192.168.1.10/24) to calculate network details.
How it works: This tool calculates the network address, subnet mask, broadcast address, usable host range, and more for any IPv4 subnet.
- Network Address: The first address in the subnet, used to identify the network.
- Broadcast Address: The last address, used to send data to all hosts in the subnet.
- Usable Hosts: All addresses between the network and broadcast (except /31 and /32).
- Subnet Mask: Shows which part of the IP is the network portion.
- Wildcard Mask: The inverse of the subnet mask, useful in some firewall rules.
Examples:
- 192.168.1.10/24 → Network: 192.168.1.0/24, Mask: 255.255.255.0, Hosts: 254
- 10.0.0.1/8 → Network: 10.0.0.0/8, Mask: 255.0.0.0, Hosts: 16777214
- 172.16.5.100/30 → Network: 172.16.5.100/30, Mask: 255.255.255.252, Hosts: 2
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This calculator is for IPv4 only. CIDR /31 and /32 are handled according to RFC 3021.
All calculations are performed locally in your browser.