Subnet Calculator

IP Address Subnet Mask

Start Host Address
End Host Address
Max No. of Hosts
Network Address
Broadcast Address
Network Class
Network Address Size Bits
Host Address Size Bits
IP Address Binary
Network Address Binary
Broadcast Address Binary
Subnet Mask Binary
Details

Subnet Calculator – Fast & Accurate IP Subnetting

The Subnet Calculator is an easy tool for network engineers, sysadmins, and students to calculate subnet masks, CIDR notation, IP address ranges, broadcast addresses, and the total number of usable hosts in a subnet.

How to Use the Subnet Calculator

Just enter:

  • An IP address (e.g., 192.168.1.0)
  • Select the subnet mask or CIDR prefix (e.g., /24)

The calculator will instantly generate the network ID, broadcast address, usable host range, wildcard mask, and total hosts.

How Subnetting Works

Subnetting divides a larger network into smaller, manageable sub-networks. It uses a subnet mask to separate the network and host portions of an IP address.

Example: For IP 192.168.1.0/24:
Subnet Mask: 255.255.255.0
Network ID: 192.168.1.0
Broadcast Address: 192.168.1.255
Usable Hosts: 254

Example

IP Address: 10.0.0.0
Subnet Mask: 255.255.255.240 (/28)
→ Network ID: 10.0.0.0
→ First Host: 10.0.0.1
→ Last Host: 10.0.0.14
→ Broadcast: 10.0.0.15
→ Usable Hosts: 14

Common Use Cases

  • Designing secure network architectures
  • Splitting large networks for better performance
  • Planning IP address allocation
  • Training for networking certifications
  • Troubleshooting network configurations

Why Use a Subnet Calculator?

Manual subnet calculations are error-prone and time-consuming. This tool instantly gives you accurate IP ranges and subnet details, so you can plan, configure, or troubleshoot networks with confidence.

Frequently Asked Questions (FAQs)

What is CIDR notation?

CIDR (Classless Inter-Domain Routing) shows the number of bits used for the network prefix, e.g., /24 means 24 bits for network, 8 bits for hosts.

What is a wildcard mask?

A wildcard mask is the inverse of the subnet mask, used in access control lists (ACLs) for routing.

Can I calculate multiple subnets?

Yes. You can input different CIDR ranges to divide a network into multiple smaller subnets.

What is a usable host?

It’s an IP address assignable to a device. The first and last IP in the range are reserved for network ID and broadcast.

Is this for IPv4 or IPv6?

This calculator works mainly for IPv4 subnetting. For IPv6, use a dedicated IPv6 subnet calculator.


Related tools: Bandwidth Calculator, Checksum Calculator.