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Subnet Calculator
Calculate network address, broadcast, usable IPs, and more from any IPv4 + CIDR.
Subnet Calculator – Calculate Network Address, Broadcast, CIDR, and Usable IPs
Our free Subnet Calculator helps you determine network address, broadcast address, first and last usable IPs, total hosts, and wildcard mask from any IPv4 and CIDR input. Designed for networking professionals and learners alike, this tool makes subnetting simple, visual, and error-free.
What is a Subnet Calculator?
A Subnet Calculator is a networking utility that computes detailed information about an IP subnet. By entering an IP address and subnet mask (or CIDR notation), users can instantly view the network boundaries, usable host ranges, and critical metadata about the subnet.
Why Do You Need a Subnet Calculator?
- To plan network segments efficiently
- To avoid IP conflicts and optimize address usage
- To simplify IP planning and documentation
- To help understand CIDR notation and binary subnetting
Key Features
- Supports any valid IPv4 address and CIDR input (e.g., /24)
- Displays network address, broadcast address, and subnet boundaries
- Calculates first and last usable IPs and total host count
- Shows wildcard mask for firewall rules and ACLs
- One-click Copy, Print, Export, and Send Feedback buttons
- ARIA-accessible and mobile-responsive design
How to Use This Tool
- Enter a valid IPv4 address (e.g., 192.168.1.100)
- Select a subnet mask using the dropdown or type /CIDR directly
- Click “Calculate”
- View all results: Network address, Broadcast, Usable IP range, Total Hosts
- Use Copy or Export to save results, or Send Feedback to reach us
Common Use Cases
- Subnetting for enterprise networks and VLAN design
- Educational tools for students learning CIDR and IP math
- Firewall and ACL rule planning
- Cloud and DevOps network provisioning
Frequently Asked Questions
A: Yes. The tool will auto-split the IP and CIDR and calculate accordingly.
A: A wildcard mask is the inverse of the subnet mask, commonly used in firewall and ACL configurations.
A: No. This calculator is currently designed for IPv4 subnetting. IPv6 support is coming soon.
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Disclaimer
This Subnet Calculator is provided for informational and educational purposes only. Always verify critical calculations in production environments. NetSecureTools.com is not responsible for any configuration errors arising from misuse.