IP Subnet Calculator
Calculate IPv4 network properties, subnet masks, and CIDR notation
Network Configuration
Enter each octet (0-255)
Network prefix length (1-32)
Select subnet mask
Network Information
Common Network Examples
Home Network
Network: 192.168.1.0/24
Hosts: 254 usable
Range: 192.168.1.1 - 192.168.1.254
Large Private Network
Network: 10.0.0.0/8
Hosts: 16,777,214 usable
Range: 10.0.0.1 - 10.255.255.254
Medium Private Network
Network: 172.16.0.0/16
Hosts: 65,534 usable
Range: 172.16.0.1 - 172.16.255.254
Small Subnet
Network: 192.168.1.0/26
Hosts: 62 usable
Range: 192.168.1.1 - 192.168.1.62
CIDR Quick Reference
Private IP Ranges
Subnetting Tips
Use /30 for point-to-point links (2 usable hosts)
Reserve network and broadcast addresses
Plan for future growth when choosing subnet sizes
Use private IP ranges for internal networks
Understanding IP Subnetting
What is Subnetting?
Subnetting is the practice of dividing a network into smaller sub-networks (subnets). It helps optimize network performance, improve security, and efficiently use IP address space.
Key Components
- •Network Address: First address in the subnet
- •Broadcast Address: Last address in the subnet
- •Host Range: Usable addresses for devices
- •Subnet Mask: Defines network vs host portion
CIDR Notation
Format
192.168.1.0/24
- • IP Address: 192.168.1.0
- • Prefix Length: /24 (24 network bits)
- • Host Bits: 32 - 24 = 8 bits
- • Total Addresses: 2^8 = 256
Calculation Formula
Total Addresses:
2^(32 - CIDR)
Usable Hosts = Total - 2 (network + broadcast)