CIDR Calculator

Category: Technology

- September 03, 2025

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Calculate network information based on IP address and subnet mask using CIDR notation. This calculator helps you determine network address, broadcast address, and available host ranges.

IP Address and Subnet

IP Address Entry

IP Address:

CIDR Prefix (Subnet Mask):

Subnet Mask:

Entry Method:

CIDR Notation

Subnet Mask

Display Options

Show binary notation

Show classful information

Show hexadecimal notation

Include network and broadcast in usable range

Network Information

Network Range

192.168.1.0 - 192.168.1.255

254 Usable Hosts

Network Address

192.168.1.0

Broadcast Address

192.168.1.255

Subnet Mask

255.255.255.0

/24

Usable Host Range

First Host:

192.168.1.1

Last Host:

192.168.1.254

Binary Notation

Description	Octet 1	Octet 2	Octet 3	Octet 4
IP Address	11000000	10101000	00000001	00000001
Subnet Mask	11111111	11111111	11111111	00000000
Network Address	11000000	10101000	00000001	00000000
Broadcast Address	11000000	10101000	00000001	11111111

Network Classification

Address Class:

Class C

Default Subnet:

/24 (255.255.255.0)

Type:

Private Network

Subnet Details

Total Addresses:

256

Usable Hosts:

254

Wildcard Mask:

0.0.0.255

Network Bits:

Host Bits:

CIDR Calculation

Network = IP_Address & Subnet_Mask

To calculate the network address, apply a bitwise AND operation between the IP address and subnet mask. The broadcast address is the network address with all host bits set to 1.

About CIDR Notation

CIDR (Classless Inter-Domain Routing) is a method for allocating IP addresses and routing IP packets. It replaced the earlier addressing architecture of classful network design, which divided the address space into classes (A, B, C, D, E) with fixed sizes.

CIDR Notation Explained

Notation Format: CIDR uses a syntax of IP address followed by a slash and number (e.g., 192.168.1.0/24).
Prefix Length: The number after the slash represents the count of leading 1 bits in the subnet mask.
Address Range: A CIDR block specifies a contiguous range of IP addresses.
Subnet Mask: The subnet mask determines which portion of an IP address refers to the network and which portion refers to hosts.

Common CIDR Blocks

/8 (255.0.0.0): 16,777,214 hosts - Used for large organisations or regional internet registries
/16 (255.255.0.0): 65,534 hosts - Typical for large organisations
/24 (255.255.255.0): 254 hosts - Common for small networks and home LANs
/27 (255.255.255.224): 30 hosts - Useful for small office segments
/30 (255.255.255.252): 2 hosts - Typically used for point-to-point links
/32 (255.255.255.255): 1 host - Represents a single host

Private IP Address Ranges

10.0.0.0/8: Class A private address range (10.0.0.0 to 10.255.255.255)
172.16.0.0/12: Class B private address range (172.16.0.0 to 172.31.255.255)
192.168.0.0/16: Class C private address range (192.168.0.0 to 192.168.255.255)
169.254.0.0/16: Link-local addresses (automatic private IP addressing)

Understanding CIDR Notation

CIDR stands for Classless Inter-Domain Routing. It's a method used to allocate IP addresses and manage network traffic. By using CIDR notation, which combines an IP address with a prefix (like /24), users can define how many IP addresses are available for use. This notation replaces older methods that grouped IPs into fixed classes, allowing for more efficient use of network space.

What’s a CIDR Calculator?

A CIDR calculator is a handy tool that helps people calculate network details using an IP address and a subnet mask. It shows crucial information like network addresses, broadcast addresses, and the range of usable hosts. This makes it easier for network administrators and tech enthusiasts to set up and manage networks effectively.

How to Input Your Data

Using the CIDR calculator is simple. You start by entering an IP address, such as 192.168.1.1, and its corresponding CIDR prefix (like /24). You can also input a subnet mask directly. The calculator will then convert this data into useful network information. It’s designed to cater to both novice and experienced users.

Results You Can Expect

Network Range: The span of addresses available within your subnet.
Network Address: The starting address for your network.
Broadcast Address: The address used to send data to all devices on the network.
Subnet Mask: Displays the mask in both decimal and CIDR format.

Advanced Features of the Calculator

This CIDR calculator isn’t just basic. It offers advanced options that let users view data in different formats. You can see binary and hexadecimal notations, which are useful for deeper network analysis. Also, you can include network and broadcast addresses in the usable range, giving you a clearer picture of your network configuration.

Why Use a CIDR Calculator?

Using a CIDR calculator simplifies network management. It reduces the chances of errors when subnetting IP addresses. By quickly providing critical information, it saves time and ensures that networks are properly configured. This is especially helpful for IT professionals and anyone working with multiple networks.

Additional Learning Resources

CIDR Blocks: Familiarize yourself with common CIDR blocks like /24 or /16 to understand their uses.
Private IP Ranges: Learn about private ranges like 192.168.0.0/16 for home networks.
Subnetting Guides: Explore guides on subnetting to enhance your networking skills.

Getting Started with Your Networking Needs

With the CIDR calculator, you're equipped to tackle your networking needs efficiently. Whether you're setting up a home network or managing a larger enterprise setup, this tool provides clear and essential data at your fingertips. Understanding CIDR notation and using this calculator will empower you to better manage your IP allocation and network configurations.