What is a Subnet Calculator?

A subnet calculator is a tool that helps you divide an IP network into subnets. It calculates network address, broadcast address, usable host range, subnet mask, wildcard mask, and more. Subnetting is essential for efficient IP address management and network security.

CIDR (Classless Inter-Domain Routing) notation (e.g., 192.168.1.0/24) is commonly used to represent subnets.

How to Use This Tool

1. Enter an IPv4 address (e.g., 192.168.1.0).
2. Adjust the CIDR slider or input (e.g., /24).
3. View real-time results: network, broadcast, host range, masks, and more.
4. Click the copy icon to copy any result for use in configs or documentation.

This tool is perfect for network engineers, sysadmins, students, and anyone working with IP addressing.

CIDR to IP Range Example

For 192.168.1.0/24:

• Network Address: 192.168.1.0
• Broadcast Address: 192.168.1.255
• Usable Hosts: 192.168.1.1 – 192.168.1.254
• Subnet Mask: 255.255.255.0
• CIDR Notation: /24

VLSM Subnetting Guide

VLSM (Variable Length Subnet Mask) allows you to create subnets of different sizes within the same network. This is useful for optimizing address allocation. Example: splitting 192.168.1.0/24 into /26, /28, etc., for different departments.

To perform VLSM, calculate the largest required subnet first, assign it, then move to the next largest, and so on. This tool helps you visualize and plan VLSM subnetting.

IPv6 Subnetting Explained

IPv6 uses 128-bit addresses and supports much larger address spaces. Subnetting in IPv6 is typically done using /64 blocks. While this tool currently focuses on IPv4, future updates may include IPv6 support.

IPv6 subnets are written like 2001:db8::/64. The principles of network, host, and prefix length are similar to IPv4.

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