IP Subnet Calculator

Analyze an IPv4 address with a CIDR prefix and show the resulting network, mask, range, and host counts.

Preparing IP Subnet Calculator

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Input

Enter an IPv4 address and the CIDR prefix length to see the full subnet breakdown. This tool shows the result instantly without step-by-step output.

Input summary

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How to use IP Subnet Calculator

Provide the address and prefix, and the calculator will translate the CIDR notation into the network details administrators typically need.

What this calculator is for

This calculator is for network planning, classroom subnetting practice, and troubleshooting when an IPv4 prefix needs to be converted into concrete address ranges.

Tips

Use the host address that actually belongs to the subnet; the calculator will still derive the network boundary from it.
Remember that very small prefixes can leave few or no usable host addresses once network and broadcast reservations are considered.