🌐 Subnet Calculator

Calculate IP subnets, network addresses, broadcast addresses, and host ranges for network planning.

Enter an IPv4 address
/
Number of network bits (1-30)
Enter subnet mask in dotted decimal notation
Number of hosts needed (minimum subnet will be calculated)

Common Subnet Masks

/24 255.255.255.0 254 hosts
/25 255.255.255.128 126 hosts
/26 255.255.255.192 62 hosts
/27 255.255.255.224 30 hosts
/28 255.255.255.240 14 hosts
/30 255.255.255.252 2 hosts

Subnet Calculator Features

🔧 Multiple Input Methods

Calculate subnets using CIDR notation, subnet masks, or required host count. Flexible input for different networking scenarios.

📊 Complete Analysis

Get network address, broadcast address, host ranges, and binary representations for comprehensive subnet planning.

🌐 Network Planning

Perfect for network administrators, students, and IT professionals planning IP address allocations and network segmentation.

Subnet Calculator FAQ

What is CIDR notation?
CIDR (Classless Inter-Domain Routing) notation shows an IP address followed by a slash and number indicating network bits. For example, 192.168.1.0/24 means 24 bits are used for the network portion.
How do I choose the right subnet size?
Consider the number of hosts needed in each subnet. Choose the smallest subnet that accommodates your hosts plus growth. Remember that 2 addresses (network and broadcast) are not usable for hosts.
What's the difference between network and broadcast addresses?
The network address (all host bits 0) identifies the subnet itself. The broadcast address (all host bits 1) is used to send data to all devices in the subnet. Neither can be assigned to hosts.
What is a wildcard mask?
A wildcard mask is the inverse of a subnet mask. It's used in access control lists (ACLs) and routing protocols. Where subnet mask has 1s, wildcard mask has 0s, and vice versa.