IP Subnet Calculator

Enter your IPv4 or IPv6 address in the IP calculator fields below. It will quickly find your subnet mask, CIDR, and full IP range with just a single click. It’s fast and highly accurate.

IPv4 Subnet Calculator

  • 128.0.0.0 /1 (2,147,483,648 IPs)
  • 192.0.0.0 /2 (1,073,741,824 IPs)
  • 224.0.0.0 /3 (536,870,912 IPs)
  • 240.0.0.0 /4 (268,435,456 IPs)
  • 248.0.0.0 /5 (134,217,728 IPs)
  • 252.0.0.0 /6 (67,108,864 IPs)
  • 254.0.0.0 /7 (33,554,432 IPs)
  • 255.0.0.0 /8 (16,777,216 IPs)
  • 255.128.0.0 /9 (8,388,608 IPs)
  • 255.192.0.0 /10 (4,194,304 IPs)
  • 255.224.0.0 /11 (2,097,152 IPs)
  • 255.240.0.0 /12 (1,048,576 IPs)
  • 255.248.0.0 /13 (524,288 IPs)
  • 255.252.0.0 /14 (262,144 IPs)
  • 255.254.0.0 /15 (131,072 IPs)
  • 255.255.0.0 /16 (65,536 IPs)
  • 255.255.128.0 /17 (32,768 IPs)
  • 255.255.192.0 /18 (16,384 IPs)
  • 255.255.224.0 /19 (8,192 IPs)
  • 255.255.240.0 /20 (4,096 IPs)
  • 255.255.248.0 /21 (2,048 IPs)
  • 255.255.252.0 /22 (1,024 IPs)
  • 255.255.254.0 /23 (512 IPs)
  • 255.255.255.0 /24 (256 IPs)
  • 255.255.255.128 /25 (128 IPs)
  • 255.255.255.192 /26 (64 IPs)
  • 255.255.255.224 /27 (32 IPs)
  • 255.255.255.240 /28 (16 IPs)
  • 255.255.255.248 /29 (8 IPs)
  • 255.255.255.252 /30 (4 IPs)
  • 255.255.255.254 /31 (2 IPs)
  • 255.255.255.255 /32 (1 IPs)

IPv6 Subnet Calculator

Subnet Calculator

Our subnet mask calculator is an online free tool that helps you instantly find the range of IPs in a subnet, both for IPv4 and IPv6 addresses. It is perfect for planning, troubleshooting, and understanding how your IP fits into the bigger network. 
By using this IP address calculator you receive all the information completely organized in a well-structured manner. No need to go through a complex process. Plus, no registration or sign-up is required.

How to Use Our Subnet Calculator?

When you visit our subnet calculator online, you will see two separate sections. These include the IPv4 subnet calculator and the IPv6 subnet calculator. 
Each of these is meant to calculate the netmask details for the specific IP version you are working with.

Using IPv4 Subnet Calculator

To calculate the subnet details with this netmask calculator for an IPv4 address, follow these steps:

1. Select Network Class

Start by selecting the network class your IP address belongs to. You can choose from Class A, B, and C, in which:

  • Class A is for larger networks
  • Class B is for medium-sized networks
  • Class C is for small networks

If you are not sure about the network class for your IP, leave it to any. Our IPv4 calculator has the ability to auto-detect it.

2. Choose Subnet

Click the dropdown menu under the “Subnet” field. You will see a list of subnet masks. Select the one that matches your IP range or the division you need.

3. Enter Your IPv4 Address
Once you have selected the Class and Subnet, simply enter your IPv4 address in the field below the “Subnet”. 

4. Click the Action Button
Click the green “Check” button at the bottom of the section. This IP subnet calculator will instantly display results, showing your IP range information along with other details. 

Using IPv6 Subnet Calculator

Below are the steps to follow to calculate the subnet details for an IPv6 address.

1. Choose Subnet
Inside the second box, under the subnet field, use the dropdown menu to select the subnet prefix (e.g., /64, /56, /48). These values actually tell how broadly or narrowly your IPv6 block is segmented.
2. Enter Your IPv6 Address
Type in or paste your IPv6 address in the designated field.
3. Click the Action Button
Press the green “Check” button. The calculator will calculate and display all relevant subnet details for your IPv6 input.

What Results Do You Get with our online subnet calculator?

When you use our network calculator, it provides you with detailed results in three separate blocks that are as follows:

  • Block 1: Subnet Block Details
  • Block 2: Network List
  • Block 3: IP List

Next provided is the detailed explanation for each.

Block Details:

  • IP: The IP address that you entered
  • Netmask: These are the values of the subnet mask associated with your selection.
  • CIDR: CIDR (Classless Inter-Domain Routing) notation. It shows IP + prefix. As an example, if the CID is “255.255.255.0/24”, the values before the slash “/” will be the IP address, and after the slash “/” will be the prefix.
  • Block Size: Number of IPs in the selected block.
  • Broadcast: The last IP in the block. It is usually used for sending network-wide packets.
  • Network: The first IP address in the block. This address is used for identifying the subnet itself.
  • Prefix Length: Same as CIDR, displayed numerically after the slash “/”.

Network List:

The Network List displays how your input subnet split into smaller network chunks. The entries inside the list show subnets in CIDR format. Each value inside this list represents a separate network slice. 
This information is very helpful when it comes to dividing a large network block into small subnets. Or if you are doing network segmentation or VLAN planning.

IP List:

This list shows all the IP addresses that fall within the subnet block for the IP provided. This list is based on the subnet and block size selected and will include all assignable IPs within that range.
The IP list is beneficial for networking professionals who need to assign static IP addresses or create IP reservation plans.

Why Use Our Subnet Mask Calculator?

The following are the reasons you should use our IP address calculator:

  • Perform instant subnet calculation, eliminating the need for complex manual math work.
  • Provide you with detailed results, including subnet block details, network information, and an IP list.
  • Let's perform the calculation for both IPv4 and IPv6 addresses.
  • Free and easy to use. No installation or signup is needed.
  • Highly compatible. You can use it on devices with any screen size, such as smartphones, laptops, tablets, and desktops.

What is Subnet Mask?

A subnet mask is a number that indicates which part of an IP address represents the network and which part represents the device (host). It tells how many IP addresses can be on a single network. It helps divide a large network into smaller, manageable parts called subnets.
The longer the subnet mask (more bits set to 1), the smaller the number of available IPs in that network, and the more subnets you can create. 
Regarding the length of the subnet mask, it varies with the IP type. For IPv4 addresses, the length is 32 bits, and for IPv6 addresses, the length is 128 bits.