Subnet Calculator
Enter an IPv4 CIDR block to get the network and broadcast addresses, usable host range, netmask, wildcard mask, and host count. This one runs entirely in your browser.
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What this tool does
Calculate IPv4 network boundaries from CIDR notation.
How to use it
Enter an IPv4 address and prefix length, then inspect the network, broadcast and host range.
Worked example
192.168.1.10/24 gives network 192.168.1.0, mask 255.255.255.0 and broadcast 192.168.1.255.
Limitations and checks
IPv4 only. /31 and /32 have special endpoint semantics; do not apply the ordinary network-and-broadcast subtraction to every prefix.
How your data is processed
Address arithmetic runs locally in the browser and does not contact or scan the entered network.
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