IP Subnet Calculator

Subnet Calculator
Calculate network, broadcast, and host range for an IPv4 subnet.

What this calculator does

The subnet calculator takes an IPv4 address and CIDR prefix length and computes the network address, broadcast address, first and last host, and the number of usable hosts in the subnet.

Use it when designing or troubleshooting networks, checking whether an address belongs to a subnet, or planning how to split a larger network into smaller subnets.

How to use this calculator

Enter your information in the fields above, run the calculation, and review the result to understand what it means for your situation.

How to interpret your result

Look at the output in the context of your overall goals rather than in isolation. Consider how sensitive the result is to changes in your inputs (for example, adjusting the amount, rate, or time) to understand which factors matter most.

Limitations and notes

This tool is a simplified model and does not capture every nuance of real life. Treat it as a planning aid, not a guarantee. For important financial or health decisions, combine these results with professional advice and more detailed analysis.