FREE Online IP Subnet Calculator with Custom Mask

FREE Online IP Subnet Calculator with Custom Mask

This is a simple and very powerful tool for calculating IP, subnet IP address, subnet mask, wildcard mask, and IP class types, and many other details.

This FREE tool can be used for learning and studying networking. Give IP address and subnet mask as input and you will get all the IP address details.

Here is the detail about each field used in the IP subnet calculator.

1. IP Address

The IP (Internet Protocol) address is the address assigned to the device (computer) by which other devices identify it.

This IP address is a part of the network layer (3rd layer in the OSI layer model architecture).

It is 32 bits address and split into four-octave.



where x is in the range of 0 (00000000) to 255 (11111111).

By default, IP address is considered as IPv4 IP address. There is also an IPv6 IP address. You can read the difference between IPv4 and IPv6 addressing.

2. IP Class Type

All the IP addresses are classified into five types called class A, class B, class C, class D, and class E. This classification is based on the starting bits of the first octave

IP Address Range (Theoretical) Start-Bits Application (Used for)
A to 0 Very large networks
B to 10 Medium networks
C to 110 Small networks
D to 1110 Multicast
E to 1111 Experimental

Read detail about different IP address class types and their uses.

3. Subnetting

For the sake of simplicity, there is a provision to divide the network into multiple subnets. This process is called as subnetting.

This is a simple definition. There are multiple benefits of subnetting. Read it in detail.

4. Netmask

Some of the starting bits in the 32 bits IP address are used to identify the network. The number of these bits is called as netmask (says n).

Remaining bits (h = 32-n) are used to identify the host in the network.

5. Host/Net

It is the number of hosts (connected devices) present in the network or subnet.

It is calculated as 2^h-2.

  • 2^h is the number of unique IP addresses that can be formed by h number of bits.
  • The IP address with all host bits as zeros and all host bits as ones are special IP addresses. These special IP addresses are not assigned to any host in the network. So, we have subtracted two from the actual number.

6. Example

n = 23 (netmask)
h = 32-n = 32-23 = 9 (host bits)
Number of host/net = 2^9 - 2 = 512 - 2 = 500

7. Broadcast IP Address

It is the IP address that has all host bits as ones.

Whenever the network receives any packet which has broadcast IP address as destination IP address, it sends the packet to all the host in the network. This process is called as broadcasting.

8. Wildcard IP Address

Wildcard IP address can be obtained by inverting all the bits of the broadcast IP address. This means, all the network bit becomes zeros and all the host bit becomes ones.

This is all about different terminologies used in the IP Subnet calculator. If you have any questions, comment me below.

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