IP Subnet Calculator

Calculate network subnets, host ranges, and subnet information for IP addresses

Network Configuration

Enter IP address and subnet information

IP Address Classes

Class A: 1.0.0.0 - 126.255.255.255 (/8)
Class B: 128.0.0.0 - 191.255.255.255 (/16)
Class C: 192.0.0.0 - 223.255.255.255 (/24)
Private Ranges:
  • 10.0.0.0 - 10.255.255.255 (/8)
  • 172.16.0.0 - 172.31.255.255 (/12)
  • 192.168.0.0 - 192.168.255.255 (/16)

Common CIDR Notations

/8 → 255.0.0.0 (16,777,214 hosts)
/16 → 255.255.0.0 (65,534 hosts)
/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)
/29 → 255.255.255.248 (6 hosts)
/30 → 255.255.255.252 (2 hosts)

Subnetting Guide

Key Concepts:

  • • Network bits identify the network
  • • Host bits identify individual hosts
  • • Subnet mask separates network from host bits
  • • CIDR notation shows prefix length (/24)
  • • Wildcard mask is inverse of subnet mask

Calculations:

  • • Total hosts = 2^(32-CIDR)
  • • Usable hosts = Total hosts - 2
  • • Network address: first address
  • • Broadcast address: last address
  • • First host: Network + 1
  • • Last host: Broadcast - 1