IP address (IPv6):
Netmask (hexadec):
Host range: -

Subnet calculator

The entire internet is too large and therefore it must be logically divided into hierarchical, smaller parts that are called subnets. This division is important for the performance and clear arrangement of the entire network. IP Subnet Calculator is a calculator of subnets that allows generating information on the subnet according to specified parameters.

IP Subnet Calculator automates the process of calculation of the number of subnets and the number of their guests.


Internet Protocol version 4, IPv4, is basically a synonym for modern Internet and it is also its main building block. Each device that is connected to the global Internet network must be assigned its own IP address that is unique and works on the basis of a numerical code. Without IP addresses the routers in the network would not know where to send the datagram.

This solution was first described in 1981 and became the first truly widespread IP protocol. If we want to deal with technical details of IPv4 we have to start by saying that it is used in networks where there is a packet switching. So the data are not sent as a whole but are divided in smaller parts.

The architecture of IPv4 is 32 bits - meaning that it consists of 4 octets separated by periods. A familiar format (for example, in decimal looks like this - 11000000.10101000.00001001.00001001. Decimal system is used only because of clearer arrangement; the network devices convert IPv4 to a binary system in which they work.

In the 1990s there have been some concerns about the fact that there will not be enough IPv4 addresses and that they will run out very soon. Everything has been put forward by the exponential development of the Internet but also by wasting IP addresses. Telling fact may be that the original design of IP protocol did not allow for the emergence of subnets. The number of devices in the network was determined by classes that have a major disadvantage - it is difficult to regulate their scope. Again, there is wasting. One solution was the introduction of masks which split into different subnets. Example of an IP address with mask is The mask is the number after the slash and it represents a certain part of the network. Thus providers did not have to assign the entire class, but only a part of the network that was more appropriate.

IPv4 did run out, it happened in February 2011. His successor is IPv6.


The successor of IPv4, called IPv6, is a protocol that should solve the problem of a lack of address space. The main and most fundamental difference is the transition to 128-bit encryption. In practice, this allows assignment of billions of IP addresses to each of the people living on the planet. And the space would still not be exhausted. This is not the only advantage. IPv6 has a simple structure and its new routing capabilities increase overall performance which was inadequate in IPv4. IPv6 was a crucial improvement necessary for the further development of the Internet.

The transition from IPv4 to IPv6 was not noticed by users. However, the situation was different for internet providers who had to take coming of the new standard into account. IPv6 is not backwards compatible with IPv4 but in practice it is not possible for IPv6 users to be cut off from most of the Internet which still uses and will use the old solution. For this reason various converters are used to convert one protocol to another.

Technical improvements are apparent in the IPv6 datagram. Despite the use of 128 bit encryption and thus quadrupling the length of the address the datagram header is only twice as long compared to IPv4.

What is my IP address?

This is the question that most of Internet users will encounter at least once in their lifetime. There are several ways to find out what the IP address is. This list is certainly not complete. We list only the most practical and easiest options.

It is important to say that IP addresses are divided into static and dynamic. You cannot connect to the Internet without an IP address. A common user is basically not able to tell the difference between the two. Broadly speaking, a static IP address is permanently assigned by the operator and is constant. A dynamic address can be changed every time you connect to the Internet. Differences between public and non-public IP rest mainly in security, but today when various protective elements are both commonplace and necessity this aspect is disappearing.

To find all available information about an IP address and about your connection in general it is good to visit a specialized website that can do it.

Generally, you will find following information:

My IP address (IPv4 or IPv6) - a unique address that identifies your computer on the Internet.

Hostname - This is in fact a text transcript of an IP address which also serves for identification in the network.

Local IP address - the IP address which is operated in LAN, i.e. the local network (for example, a household or a company). Here you can simply find the IP directly on your PC. Open a command prompt - Start -> Run -> and typing: cmd. Here you just have to type: ipconfig and press enter.

Websites detecting IP address will often provide lots of other data, too. For example: location, operating system, browser, browser language, screen resolution and many other more or less useful data.

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