Cloud Egress Cost Calculator

Compare egress pricing across AWS, GCP, and Azure — internet egress, inter-region transfer, CDN rates, and practical strategies to cut your data transfer bill.

Understanding Cloud Egress Pricing

Egress costs — charges for data leaving a cloud provider's network — are one of the most misunderstood and frequently underestimated components of cloud bills. Unlike compute or storage costs that scale predictably with usage, egress costs can spike dramatically as applications grow, and they create significant friction when attempting to migrate or distribute workloads across providers.

The three major cloud providers (AWS, GCP, Azure) all follow a tiered pricing model for internet egress: the first tier is priced highest, with rates declining for higher monthly volumes. However, even the lowest tiers remain substantially higher than the actual cost of bandwidth, as egress pricing is also a customer retention mechanism.

Understanding the different egress categories is essential: Internet egress (cloud to the public internet), inter-region transfer (between regions within the same cloud), inter-zone transfer (between availability zones in the same region), and CDN egress (via the provider's content delivery network). Each has different rates, and optimizing where you fall in each category can dramatically reduce costs.

Internet Egress Rate Comparison — AWS vs GCP vs Azure

Rates shown are for US/EU regions (Zone 1). Asia-Pacific and South America regions are typically 30–50% higher. Prices are approximate — always verify at each provider's pricing page.

Inter-Region Transfer Costs

Inter-region transfers — data moving between two regions within the same cloud — are a common hidden cost in multi-region architectures. Read replicas, cross-region replication, and active-active deployments all generate inter-region traffic that can add up quickly at scale.

CDN Egress vs Direct Egress

For user-facing content, using the cloud provider's CDN reduces egress costs dramatically. CDN pricing leverages the provider's bulk bandwidth agreements with internet exchanges, passing savings to customers. The trade-off is that CDN pricing applies to edge-to-user delivery, not all traffic patterns — API calls, database queries, and server-to-server communication cannot be served from CDN.

CDN rates shown are for US/EU regions, first 10 TB tier. Origin-to-CDN transfer is typically free within the same provider. Cloudflare R2 is an S3-compatible object store with zero egress fees.

Strategies to Reduce Egress Costs

• Co-locate compute and storage: The single most impactful optimization. Keep your application servers and databases in the same region. Cross-region reads from a database can silently generate large inter-region bills at $0.02–$0.08/GB.
• Use CDN for all public content: Images, videos, static assets, and downloadable files should always go through a CDN. CloudFront and Azure CDN offer the best rates at high volumes. Consider Cloudflare (external CDN) as a zero-egress alternative — traffic from origin to Cloudflare is free for AWS if you use Cloudflare's Bandwidth Alliance partnerships.
• Enable compression: Gzip or Brotli compression on HTTP responses can reduce text-based transfer volume by 60–80%. This reduces both billable egress and improves end-user latency. Enable at the web server level (nginx, Apache) or CDN level for maximum coverage.
• Use PrivateLink / Private Service Connect: AWS PrivateLink and GCP Private Service Connect let you access services over the provider's backbone rather than the public internet, often at lower rates and without internet egress charges. Particularly valuable for high-volume service-to-service communication.
• Same-AZ communication: In AWS, traffic between EC2 instances in the same Availability Zone using private IPs is free. Explicitly placing related services in the same AZ (with redundancy in a second AZ) can eliminate cross-AZ charges for hot paths.
• Consider Cloudflare R2 for object storage: R2 is S3-compatible, costs $0.015/GB/month for storage, and has zero egress fees to the internet via Cloudflare's CDN. For applications with high read traffic on stored objects (images, files), this can be dramatically cheaper than S3 + CloudFront at scale.
• Audit and right-size logging and monitoring: Verbose logs, metrics, and traces sent across regions or to external SIEMs can generate surprising egress. Consider filtering at source, using provider-native monitoring, or using agents that batch and compress before sending.

Egress Cost Examples at Scale

To illustrate how egress costs accumulate, consider a media platform streaming 100 TB/month of video to end users from AWS S3 in us-east-1:

• Direct S3 egress (no CDN): First 1 TB at $0.09 = $92 + remaining 99 TB at $0.085–$0.07 = ~$7,600/month. Total: ~$7,700/month.
• Via CloudFront CDN: 100 TB at ~$0.008/GB = ~$800/month. Savings: ~$6,900/month (90% reduction).
• Via Cloudflare R2 + CDN: Storage cost (~$1,500/month for 100 TB stored) + $0 egress. Total: ~$1,500/month for storage only. Significant savings if read-to-write ratio is high.

At this scale, the CDN alone saves over $80,000 per year compared to direct egress. For any application serving significant user-facing content, CDN adoption is the highest-ROI optimization available.