IP Subnet Calculator

Category: Technology
- April 20, 2025
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IP Subnet Calculator

Calculate network information including subnet mask, network address, broadcast address, and usable host range for both IPv4 and CIDR notation.

Network Information

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Display Options

About IP Subnetting

IP subnetting is the process of dividing an IP network into sub-networks to improve security, network performance, and address allocation efficiency.

Common Subnet Masks
CIDR Subnet Mask Usable Hosts
/24 255.255.255.0 254
/25 255.255.255.128 126
/26 255.255.255.192 62
/27 255.255.255.224 30
/28 255.255.255.240 14
/29 255.255.255.248 6
/30 255.255.255.252 2
/31 255.255.255.254 0*
/32 255.255.255.255 1**

* RFC 3021 allows /31 networks for point-to-point links
** Single host address

Formula to Calculate Total IP Addresses:
Total IPs = 2(32 − CIDR Prefix)

Formula to Calculate Usable IP Addresses:
Usable IPs = 2(32 − CIDR Prefix) − 2
(Note: For /31 and /32, special rules apply based on RFC standards)

What Is the IP Subnet Calculator?

The IP Subnet Calculator is a helpful tool for network planning. It takes an IP address and either a subnet mask or CIDR prefix and gives you important network details. These include the network and broadcast addresses, number of usable IPs, and IP address class. It can also show the binary and hexadecimal formats of the addresses.

Why Use This Tool?

This calculator simplifies subnetting tasks that are often used in networking and IT setups. It eliminates manual calculations, reduces errors, and helps users quickly understand the layout of an IP subnet.

  • Works with both CIDR notation and subnet masks
  • Shows useful details like network address, usable range, and IP class
  • Optional views for binary and hexadecimal formats
  • Instant feedback with no technical knowledge required

How to Use the IP Subnet Calculator

  1. Enter an IP address (e.g., 192.168.1.1)
  2. Select the subnet format: CIDR or Subnet Mask
  3. Enter the CIDR prefix (like 24) or the subnet mask (like 255.255.255.0)
  4. (Optional) Check the boxes to show binary and hexadecimal formats
  5. Click Calculate to see the results
  6. Use Reset to start over

Who Can Benefit From This?

This tool is useful for:

  • Students learning about computer networks
  • IT professionals planning IP ranges
  • Home users setting up routers or local networks
  • Anyone curious about IP addressing

Even those using other tools like a Download Speed Calculator, Transfer Speed Calculator, or Bottleneck Calculator may find this tool essential when configuring systems or optimizing network settings.

How This Calculator Helps

When configuring devices or allocating IP addresses, understanding the subnet range ensures efficient use of resources and prevents conflicts. For example, determining the number of usable IPs in a subnet helps when assigning devices on a local network or when planning multiple subnets in larger systems.

This tool provides instant results and can be accessed from devices like an iMac, acting as a reliable iMac computing tool or Apple desktop calculator to support your network management tasks.

Frequently Asked Questions (FAQ)

Q: What is a CIDR prefix?

A CIDR prefix is a shorthand for the subnet mask. For example, /24 equals 255.255.255.0. It tells how many bits in the IP address are used for the network.

Q: What is the difference between subnet mask and CIDR?

They're two ways of showing the same thing. A subnet mask is written in dotted-decimal form. CIDR is a compact version that shows the number of bits used for the network portion.

Q: Can I use this calculator for /31 or /32?

Yes. Special handling is done for these cases. /31 is commonly used for point-to-point links, and /32 is for single host addresses.

Q: What are binary and hex views for?

They help users see how IPs and subnet masks appear in different formats, which can be useful for learning or troubleshooting.

Related Tools Worth Exploring

  • Download Time Calculator: Estimate how long it will take to download a file based on your internet speed.
  • Transfer Speed Calculator: Check how fast data moves across networks.
  • Internet Speed Calculator: Evaluate the bandwidth and performance of your connection.
  • Bottleneck Calculator: Analyze system performance for gaming or hardware upgrades.
  • iMac Performance Tool: Check how your Apple desktop handles computing tasks, including network usage.

The IP Subnet Calculator is a practical and accessible resource that makes subnetting clear and efficient. Whether you're troubleshooting, learning, or planning, this tool offers accurate and fast insights—right when you need them.