Subnetting Generator

Learn and practise subnetting without sending any IP addresses to a server. This calculator runs entirely in your browser and supports IPv4 and IPv6, including quick comparison of multiple subnets.

IPv4 subnet calculator

Enter an address and prefix, then review the key values used in exams and real networks.

/0 to /32

Tip for exam practice. Try changing the prefix length and watch how the network, broadcast and host counts react.

Subnet comparison

Build a small study table of IPv4 and IPv6 subnets to compare ranges and sizes.

Version Network / Prefix Range Size

Use this table to test overlap or summarise an addressing plan. All values stay in your browser.

Host membership check

Quickly see whether a host address belongs to a given subnet.

Important notice This Subnetting Generator is an educational visualisation tool. All calculations run locally in your browser and no IP addresses, prefixes or results are transmitted to CyberLife Coach or to any third party service. The calculator does not change your network configuration. Results are provided without warranty and should always be verified before use in production environments or exam scenarios.

Want a gentle walkthrough of subnetting before using the calculator? Visit the companion guide About Subnetting.