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Subnet Calculator

Calculate IPv4 subnets, network ranges, and host addresses

calculate Subnet Calculator

Enter a valid IPv4 address

Select subnet mask length

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About Subnetting:

Subnetting divides a network into smaller sub-networks (subnets) to improve network performance and security. CIDR notation combines IP address and subnet mask (e.g., 192.168.1.0/24).

help_outline Understanding Subnetting

What is Subnetting?

Subnetting is the process of dividing a large network into smaller, more manageable sub-networks (subnets). It helps optimize network performance, improve security, and simplify network management.

CIDR Notation

Classless Inter-Domain Routing (CIDR) notation specifies network addresses and their subnet masks:

  • • Format: IP_address/Prefix_length
  • • Example: 192.168.1.0/24
  • • Prefix length indicates number of network bits

Common Subnet Sizes

/24 255.255.255.0 - 254 hosts
/16 255.255.0.0 - 65,534 hosts
/8 255.0.0.0 - 16,777,214 hosts

Network Classes

Class A: 1.0.0.0 - 126.255.255.255

Default mask: /8 (255.0.0.0)

Class B: 128.0.0.0 - 191.255.255.255

Default mask: /16 (255.255.0.0)

Class C: 192.0.0.0 - 223.255.255.255

Default mask: /24 (255.255.255.0)

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Private IP Ranges:

  • • Class A: 10.0.0.0 - 10.255.255.255
  • • Class B: 172.16.0.0 - 172.31.255.255
  • • Class C: 192.168.0.0 - 192.168.255.255

school Subnet Calculation Examples

Example 1: /24 Network

IP: 192.168.1.0/24

  • • Network: 192.168.1.0
  • • Broadcast: 192.168.1.255
  • • First Host: 192.168.1.1
  • • Last Host: 192.168.1.254
  • • Total Hosts: 254

Example 2: /28 Network

IP: 192.168.1.0/28

  • • Network: 192.168.1.0
  • • Broadcast: 192.168.1.15
  • • First Host: 192.168.1.1
  • • Last Host: 192.168.1.14
  • • Total Hosts: 14