Subnet Calculator - Calculator See


Subnet Calculator

Calculate IPv4 subnets, network address, broadcast address, subnet mask, and usable host IP ranges.

Calculator Inputs

IPv4 address (e.g. 192.168.1.100).
Subnet mask prefix length.

Calculated Results

Usable Host IP Range
192.168.1.1 – 192.168.1.254
Subnet Mask 255.255.255.0
Usable Host Count 254 Hosts
Broadcast Address 192.168.1.255
Values calculate live as you adjust inputs.

About Subnet Calculator

Computes IPv4 network boundaries, wildcard masks, usable host ranges, and broadcast IPs for network subnetting.

What is Subnet Calculator?

Computes IPv4 network boundaries, wildcard masks, usable host ranges, and broadcast IPs for network subnetting.

How to Use This Calculator

  1. Enter an IPv4 address.
  2. Select CIDR prefix length.
  3. View network ID, broadcast IP, and usable hosts.

The Mathematical Formula & Variables

Usable Hosts = 2^(32 - CIDR) - 2; Network ID = IP bitwise AND Netmask

Step-by-Step Worked Example

Scenario: Subnetting 192.168.1.100 with a /24 CIDR prefix.

  1. Host bits = 32 - 24 = 8 bits.
  2. Total addresses = 2^8 = 256.
  3. Usable hosts = 256 - 2 = 254 hosts (192.168.1.1 to 192.168.1.254).

Result: 254 Usable Hosts (/24)

Frequently Asked Questions

Why do we subtract 2 from total addresses?

The first address is reserved as the Network ID, and the last address is reserved as the Subnet Broadcast address.