VPC-Virtual Private Cloud Overview

VPC is your own private network inside AWS. Think of it as having your own private floor in a huge apartment building — isolated, yours to configure, but still inside the AWS building.

1. How Many VPCs Can You Have?

Maximum 5 VPCs per region (soft limit — you can request more from AWS)
You can have VPCs across multiple regions

Example:

Region	VPCs
us-east-1 (Virginia)	5
eu-west-1 (Ireland)	5
Total	10

2. VPC Size Limits (CIDR)

Each VPC can have up to 5 CIDR blocks. It means one VPC can have up to 5 separate IP ranges attached to it — not just one.

Your VPC
├── CIDR Block 1: 10.0.0.0/16     (65,536 IPs)
├── CIDR Block 2: 10.1.0.0/16     (65,536 IPs)
├── CIDR Block 3: 10.2.0.0/16     (65,536 IPs)
├── CIDR Block 4: 10.3.0.0/16     (65,536 IPs)
└── CIDR Block 5: 10.4.0.0/16     (65,536 IPs)

Each CIDR block must be within these size limits:

Limit	CIDR	Number of IPs
Minimum	/28	16 IPs
Maximum	/16	65,536 IPs

How the math works:

/28 → 2^(32-28) = 2^4 = 16 IPs
/16 → 2^(32-16) = 2^16 = 65,536 IPs

Why these limits? /28 ensures you have at least a few IPs to work with, and /16 keeps the network manageable.

3. Must Use Private IP Ranges Only

VPCs are private networks, so you can only use these three private IP ranges: