Subnet Calculator | Calculate IP Subnets, CIDR, Network Ranges

Subnet Calculator

Calculate IP subnets, CIDR notation, network ranges, and subnet masks

IP Address

Subnet Mask / CIDR

Calculation Options

Show binary visualization

Show all subnets

Validate input before calculation

Auto-calculate on input change

Custom Subnet Division

Network Information

IP Address

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Subnet Mask

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CIDR Notation

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Wildcard Mask

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Address Ranges

Network Address

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Broadcast Address

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First Usable IP

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Last Usable IP

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Network Details

Total Hosts

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Usable Hosts

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IP Class

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IP Type

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Binary Representation

IP Address:

Subnet Mask:

Network Address:

Frequently Asked Questions

What is subnetting and why is it important? +

Subnetting is the process of dividing a large IP network into smaller, more manageable subnetworks. It’s important for efficient IP address allocation, improved network performance, enhanced security through network segmentation, and reducing broadcast domains. Subnetting helps organizations optimize their IP address space and organize their network infrastructure logically.

What is CIDR notation? +

CIDR (Classless Inter-Domain Routing) notation is a compact way to represent IP addresses and their associated routing prefix. It’s written as an IP address followed by a slash and the number of bits in the network portion (e.g., 192.168.1.0/24). CIDR replaced the older classful network addressing system and allows for more flexible allocation of IP address space.

How do I calculate the number of usable hosts? +

The number of usable hosts in a subnet is calculated as 2^(host bits) – 2. The “-2” accounts for the network address (first address) and broadcast address (last address), which cannot be assigned to hosts. For example, a /24 network has 8 host bits (32-24=8), so it has 2^8 – 2 = 254 usable host addresses.

What’s the difference between network address and broadcast address? +

The network address is the first address in a subnet and identifies the network itself. It cannot be assigned to any device. The broadcast address is the last address in a subnet and is used to send data to all devices on that network. Packets sent to the broadcast address are delivered to every host in the subnet.

How does subnet masking work? +

A subnet mask is a 32-bit number that separates the IP address into network and host portions. The network bits are set to 1, and host bits are set to 0. When an IP address is logically ANDed with the subnet mask, the result is the network address. This process determines which subnet an IP address belongs to and whether two devices are on the same network.

Conclusion

Subnet calculation is a fundamental skill for network administrators, engineers, and IT professionals working with IP networks. Our subnet calculator provides a comprehensive tool for calculating IP subnets, CIDR notation, network ranges, and subnet masks with precision and efficiency. Understanding subnetting principles is essential for effective network design, IP address management, and troubleshooting network connectivity issues. With features like binary visualization, custom subnet division, and detailed network information, this calculator helps professionals optimize their network infrastructure and ensure proper IP address allocation. Regular use of subnet calculation tools enhances network planning capabilities and supports the implementation of scalable, secure, and well-organized network architectures.