There comes a time when the network becomes too large to manage and performance numbers hit an all-time low as a result of too much traffic. One of the most effective technique to solve this network congestion problem is to break the TCP/IP network into smaller, more manageable pieces. The practice of dividing the network is called subnetting.
Need for a IPv4 subnet calculator
Every subnet has an address to represent it and these subnets are interconnected via router. The router needs network address and subnet mask to find out whether the incoming IP packet has to be routed to any of its subnetwork. Performing network calculations can be hard at times when you have to consider different parameters as to how many subnets should I have and how many hosts should be in a subnetwork.
This subnet calculator is a handy tool for finding the number of possible subnets for any given network address block. You can choose the combination of subnets and number of hosts per subnet that suits your network and get the host address range and broadcast address for any given subnet mask. IP calculations can usually be performed mentally but it's better to have an option to double check the calculations before configuring them in the router.