IPv4 Subnet Calculator

Subnet Calculator calculates a range of possible IPs in a given IP and subnet. Enter IP and subnet in the format shown below.

  • Example IP Address Inputs
    IP & CIDR Netmask: 10.0.0.1/8
    IP & Netmask: 192.168.0.1 255.255.255.240
    IP & Wildcard mask: 172.16.2.1 0.0.1.255

Subnet Calculator Result

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About this tool:

Subnet Calculator calculates a range of possible IPs in a given IPv4 and subnet.

What is Subnetting?

The time comes when the network becomes extensive to manage, and performance numbers hit an all-time low due to too much traffic. One of the most productive techniques to solve this network overcrowding problem is to break the TCP/IP network into smaller, more controllable pieces. That practice of dividing the network into smaller, more controllable components is called subnetting.

An IP address has two main components, the network address, and the host address. The subnet mask divides the IP address into network address and host address. The subnetting technique further divides the host address into a subnet and host addresses (if an additional subnetwork is needed).

In simple words, subnetting is the process of taking the extensive network and splitting it into smaller networks for re-organization and security purposes, known as subnets.

Why Subnetting in important?

During the early stages of the internet, organizations assigned IPv4 addresses without proper management until we nearly ran out. Luckily, the creators of IP addressing came up with a way to end this wasteful practice: Dividing networks using subnetting. 

A subnet mask is a 32-bit number that masks the IP address and separates the IP address into network address and host address. A subnet mask is made by placing network bits to all "1"s and setting host bits to all "0"s. 

Two host addresses are reserved for a particular purpose in a given network and cannot be assigned to hosts. For example, the "0" address is assigned to a network address, and "255" is given to a broadcast address. Both cannot be assigned to hosts.

Need for an IPv4 Subnet Calculator

All the nodes/hosts in a subnetwork see all packets transmitted by any node in that network. That adversely affects the performance of a network under heavy traffic load because of collisions and retransmissions.

Implementing a subnet mask to an IP address divides the network address from the host address. Thus, the network bits are represented by the 1's, and the host bits are represented by 0's in the subnet mask.

A subnet calculator is a valuable tool for finding the number of possible subnets for any given network address block.

Partitioning an extensive network and allocating IP address ranges to different teams is a task that one can calculate manually. Still, it's better to have an option to double-check your subnet calculations before configuring them in the router.

IP Subnet Calculator tool divides a given IPv4 address network into the subnetworks by calculating helpful information like a Netmask, CIDR, Block size, Broadcast address, First IP and Last IP, Network address, Prefix length, and Cisco wildcard mask. You have to enter the IP Address and Subnet Mask (like 194.35.233.19/24), and this tool instantly calculates the required information for your use.

The subnetting technique is applied on IPv6 as well. You can use the IPv6 subnet calculator to calculate the IPv6 subnet address.