How a Subnet Calculator Works

A subnet calculator is a free Windows utility used for computing information on IP addresses. Using a subnet calculator will allow computation using the following factors involved in the subnet:

  • IP address
  • Network class
  • Subnet bits
  • Subnet mask
  • Mask bits

It can also calculate the maximum requirement of IP subnets and the required hosts per subnet.

IT professionals also call this type of calculator an IP Subnet Mask Calculator. They use a subnet calculator to run between masks and addresses. A mask is a filter that includes or excludes specific values. It is used to determine the subnet to which an IP address belongs.

The Addressing Scheme

The subnet calculator applies to a classified IP addressing system and strictly adheres to the rules that are in each class of addresses. Octets are referred to as the four sets of binary numbers that can be seen in an Internet Protocol (IP) address.

  • Class A address: The first octet is in the range of 1 to 126 and the binary address begins with zero.
  • Class B address: The first octet is in the range of 128 to 191 and the binary address begins with 10.
  • Class C address: The first octet is in the range of 192 to 223 and its binary address begins with 110.

The Results

The subnet calculator works to provide the following elements involved in the subnet:

  • Hexa-decimal IP address
  • Subnet IP
  • Broadcast address
  • Wildcard mask for Access Control List
  • Subnet bitmap
  • Subnet address range

The subnet calculator helps the IT student when taking certification programs that qualify him for his line of job. IT specialists take special examinations so they can work in their own respective fields.

There are online calculators that can be readily used free of charge for many who would like to use them. An example of this is found in, where you can easily use the available converting device right away. Other websites require downloading the files, which may take some time.