CDN Bandwidth Cost Calculator

About the CDN Bandwidth Cost Calculator

Content Delivery Networks accelerate content delivery by caching it at edge locations worldwide. While CDNs improve performance, bandwidth costs scale directly with traffic volume. CloudFront, Cloudflare, Fastly, and other CDNs each use different pricing models — some charge per GB delivered, others offer flat-rate or bundled pricing.

AWS CloudFront charges per GB of data transfer out with tiered pricing that decreases at higher volumes. Cloudflare offers unlimited bandwidth on paid plans. Fastly charges per GB with competitive rates. Understanding these differences is crucial for choosing a cost-effective CDN.

This calculator models per-GB CDN pricing, helping you estimate monthly costs based on your delivery volume. Compare against direct cloud egress to quantify CDN savings, and use the results to negotiate volume discounts with your CDN provider.

When This Page Helps

CDN costs scale linearly with traffic, and a sudden traffic spike or viral content can generate unexpected bills. This calculator helps you forecast CDN expenses based on expected bandwidth, compare providers, and evaluate the ROI of CDN versus direct origin serving. Many teams find CDN bandwidth is 20–50% cheaper than direct cloud egress.

How to Use the Inputs

1. Enter the total data delivered through the CDN per month in GB.
2. Set the per-GB rate for your CDN provider and plan.
3. Optionally enter HTTPS request charges (some CDNs charge per request).
4. Enter the monthly number of HTTPS requests in millions.
5. Review the total monthly CDN cost breakdown.
6. Compare against direct origin egress costs to quantify savings.

Example Calculation

Tips & Best Practices

• CloudFront data transfer starts at $0.085/GB (US/Europe) and decreases with volume.
• Cloudflare Pro ($20/mo) includes unlimited bandwidth for most sites.
• Optimize cache hit ratio to reduce origin fetches and associated egress costs.
• Use HTTP/2 and Brotli compression to reduce delivered bytes significantly.
• Set appropriate cache TTLs — longer TTLs improve hit ratios and reduce costs.
• CloudFront to S3 origin transfer is free, making it cheaper than direct S3 egress.

CDN Pricing Model Comparison

CloudFront charges per GB plus per request with tiered volume discounts. Cloudflare offers flat-rate plans with unlimited bandwidth for web traffic. Fastly charges per GB with real-time purging included. Akamai uses custom enterprise pricing. Choose based on your traffic profile: high-bandwidth video favors per-GB models; many small requests favor flat-rate.

Optimizing CDN Costs

The most impactful optimization is improving cache hit ratio. A 95% hit ratio means only 5% of requests reach your origin, dramatically reducing both CDN costs (fewer origin fetches) and origin infrastructure costs. Use cache analytics to identify low-hit-ratio paths and adjust caching rules.

CDN vs Direct Origin Serving

For static content, CDNs almost always save money versus direct egress, even before considering performance benefits. For dynamic content that cannot be cached, CDNs still add value through TLS termination, DDoS protection, and HTTP/2 optimization, though cost savings may be minimal.

Frequently Asked Questions

• Is CloudFront cheaper than direct S3 egress?

  Yes. CloudFront data transfer starts at $0.085/GB versus $0.09/GB for direct S3 egress to the internet. Additionally, S3 to CloudFront transfer is free, making CloudFront strictly cheaper for content served from S3.

• Does Cloudflare really offer unlimited bandwidth?

  Cloudflare Pro and Business plans include unlimited bandwidth for HTTP/HTTPS traffic. However, very high-bandwidth usage or non-web traffic may trigger service terms. Enterprise plans include specific SLAs for high traffic.

• How do CDN request charges work?

  CloudFront charges per request: $0.0100 per 10,000 HTTPS requests (US/EU) and $0.0075 per 10,000 HTTP requests. For sites with many small assets, request charges can be significant. Bundle assets to reduce request count.

• Should I use a multi-CDN strategy?

  Multi-CDN improves performance and availability but adds complexity and can reduce volume discounts. It makes sense for large-scale media delivery, global coverage, or mission-critical content. For most sites, a single CDN is sufficient.

• How do I improve cache hit ratio?

  Set long cache TTLs for static assets, use consistent URLs (avoid query string variations), implement cache invalidation for updates instead of short TTLs, and ensure proper Cache-Control headers on origin responses. Reviewing these factors periodically ensures your analysis stays current as conditions and requirements evolve over time.

• What about origin shield costs?

  CloudFront Origin Shield adds a caching layer between edge locations and your origin, reducing origin load. It costs $0.0090 per 10,000 requests. It's worthwhile if your origin is sensitive to traffic spikes or costly to scale.