AWS Networking Cost Summary

Networking Costs in AWS per GB – Simplified

Intra-VPC and Intra-Region Traffic

• Within the same Availability Zone (private IPs) → Free

• Between Availability Zones (same Region)
• Private IPs → $0.01 per GB
• Public / Elastic IPs → $0.02 per GB

• Between Regions → $0.02 per GB

Best Practices

• Always use private IPs where possible (lower cost, lower latency).

• Place workloads in the same AZ when HA is not required to avoid cross-AZ charges.

Minimizing Egress Traffic Network Cost

• Ingress (into AWS) → typically free

• Egress (out of AWS) → charged

Cost Optimization Tips

• Keep traffic inside AWS (avoid Internet egress).

• Co-locate compute + storage in the same Region.

• Use Direct Connect for consistent large-scale outbound traffic.

Example

• Efficient: App + DB in AWS, only small query results leave AWS.

• Inefficient: App on-prem, DB in AWS → every large query causes costly egress.

S3 Data Transfer Pricing (USA)

• Uploads to S3 → Free

• S3 → Internet → $0.09 per GB

• S3 → CloudFront → Free

• CloudFront → Internet → $0.085 per GB (cheaper + cached)

• Cross-Region Replication → $0.02 per GB

• Transfer Acceleration → +$0.04–$0.08 per GB

NAT Gateway vs Gateway VPC Endpoint

Costs

• NAT Gateway:
• $0.045/hour + $0.045 per GB processed
• S3 same-region traffic → Free
• S3 cross-region traffic → $0.09 per GB

• Gateway VPC Endpoint (S3):
• No hourly cost
• $0.01 per GB (same-region)

Takeaway