Common Private Subnet Examples (By Subnet Size)

Common Private Subnet Examples by CIDR Size

Overview
Subnetting is one of the most important skills in networking. But most training materials only explain the math — not the real-world examples. This CSV provides real, practical examples of private subnets at multiple common CIDR sizes.

Unlike generic subnetting charts, this table includes:

• Actual private IP blocks
• Network address
• Gateway address
• Broadcast address
• First and last usable host
• Total and usable host counts
• Subnet class
• Detailed usage notes (what each subnet size is typically used for)

This transforms subnetting from an academic exercise into a practical engineering reference.

What This CSV Contains

For each example subnet (e.g., /20, /21, /22, /23, /24, /25, /26, … /32) you get:

• Example subnet CIDR
• Prefix length
• Private range membership
• Class (A/B/C)
• Network address
• Gateway (.1)
• Broadcast
• First usable
• Last usable
• Total addresses
• Usable addresses
• Real-world usage notes (e.g., “Great for WiFi pools”, “Ideal for IoT segmentation”, “Point-to-point link”)

Why This Matters

Engineers often struggle with:

• Knowing which subnet size to use
• Understanding the right tool for the job
• Designing networks with best practices
• Deciding between /23 vs /24 vs /25
• Learning how broadcast and gateway positions change with subnet size

This table becomes a reference hub for network design.

You can use this on your site as:

• A subnetting tutorial
• A design guide
• A conversion helper
• A VLAN sizing reference