Ip Address Calculator

IP Address Calculator

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Results:

Network Address:

Subnet Mask:

Broadcast Address:

Usable Host Range:

Total Usable Hosts:

Wildcard Mask:

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IP Address Calculator Use

This IP address calculator is an essential tool for network administrators, IT students, and engineers to quickly determine the critical components of an IPv4 network. By entering a specific IP address and choosing a CIDR (Classless Inter-Domain Routing) prefix, you can immediately identify the network boundaries and host limitations.

Whether you are designing a new office network or troubleshooting a connectivity issue, knowing the usable host range and broadcast address prevents IP conflicts and routing errors.

IP Address Octets

Enter the four numbers (0-255) that make up the IPv4 address.

CIDR / Subnet Mask

Select the prefix length that defines the size of the network. For example, /24 is standard for small home networks.

Wildcard Mask

Commonly used in OSPF and Access Control Lists (ACLs), this shows the inverse of the subnet mask.

How IP Subnetting Works

Subnetting is the practice of dividing a large network into smaller, manageable sub-networks. The IP address calculator performs binary mathematics to find these segments. The core logic involves a Bitwise AND operation between the IP address and the Subnet Mask.

Network Address = (IP Address) AND (Subnet Mask)

• Binary Conversion: Every IP address consists of 32 bits (4 octets of 8 bits).
• AND Logic: If both the IP bit and the Mask bit are 1, the result is 1. Otherwise, it is 0.
• Broadcast Address: This is found by taking the network address and setting all host bits to 1.
• Usable Hosts: Calculated as 2ⁿ - 2, where n is the number of host bits. We subtract 2 to exclude the network and broadcast addresses.

IP Calculation Example

Example: You are assigned the IP address 192.168.10.15 with a /26 prefix. What are the network details?

Step-by-step solution:

1. Identify Subnet Mask: A /26 prefix means 26 ones followed by 6 zeros. In decimal, this is 255.255.255.192.
2. Convert IP to Binary: 192.168.10.15 becomes 11000000.10101000.00001010.00001111.
3. Calculate Network: Perform the AND operation. The last octet (15 AND 192) results in 0. So, Network = 192.168.10.0.
4. Calculate Broadcast: Flip the host bits. The last octet 00000000 becomes 00111111 (63). So, Broadcast = 192.168.10.63.
5. Determine Hosts: 2⁶ - 2 = 62 usable hosts.
6. Range: 192.168.10.1 through 192.168.10.62.

Common Questions

Why do we subtract 2 from total hosts?

In every subnet, the first address is reserved for the Network ID and the last address is reserved for the Broadcast Address. These cannot be assigned to devices like PCs or printers, so we subtract them from the total possible combinations.

What is a /24 network?

A /24 network is one of the most common subnet sizes. It provides 256 total addresses (254 usable), using a subnet mask of 255.255.255.0. It is the default for Class C networks.

Does the IP address calculator work for IPv6?

This specific calculator is designed for IPv4. IPv6 uses 128-bit hexadecimal addressing and follows different subnetting rules, though the concept of prefixes remains similar.