IP Subnet Calculator
Calculate subnet mask, network address, broadcast address, and host range.
IP Subnet Calculator
Calculate subnet mask, network address, broadcast address, and host range.
Engineering Calculation
ℹ️ Used for basic engineering ratio and product calculations
Disclaimer
Results provided by this calculator are for informational and educational purposes only. They are based on the values you enter and standard formulas, and should not be considered financial, medical, legal, or professional advice. Always consult a qualified professional before making important decisions based on these results. Roughtools makes no warranties regarding the accuracy or completeness of these calculations for your specific situation.
Frequently Asked Questions
Pro Tips
Always verify critical calculations with a second method or source — for important decisions, this tool provides a starting point, not a final answer.
Input accuracy determines output accuracy. Use precise values rather than rough estimates for the most useful results.
Run the calculation multiple times with slightly different inputs to understand the sensitivity of the result to your assumptions.
For professional, financial, medical, or legal decisions, always confirm results with a qualified professional before acting.
When to Use This Calculator
Use the IP Subnet Calculator for fast, accurate calculations without installing any software.
Understand the formula and see how changing inputs affects the result for educational purposes.
Get a quick estimate before performing more detailed analysis or consulting a professional.
Accessible from any device — no app to install, no account required, works offline after loading.
Run multiple scenarios quickly by changing one input at a time to understand sensitivities.
About the IP Subnet Calculator
This IP subnet calculator computes all key subnetting values from any IPv4 address and subnet mask (or CIDR notation) — network address, broadcast address, first usable host, last usable host, number of usable hosts, wildcard mask, and subnet class. Enter any IP address with CIDR prefix (e.g. 192.168.1.0/24) or dotted-decimal mask to see the complete subnet breakdown. Built for network engineers, system administrators, IT students, and anyone studying for CompTIA Network+ or CCNA.
How to Use the IP Subnet Calculator
- 1
Enter an IPv4 address (e.g. 192.168.1.100).
- 2
Enter the CIDR prefix length (e.g. /24) or the dotted-decimal subnet mask (e.g. 255.255.255.0).
- 3
See network address, broadcast address, first host, last host, and host count.
- 4
Review the subnet in binary to understand the host and network bit boundary.
- 5
Use the subnet divider to split a network into multiple smaller subnets.
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