CDN Cache Hit Savings Calculator
Quantify how much origin bandwidth spending drops when your CDN hits its target cache ratio. Enter your monthly transfer volume and origin egress price, then optionally set the cache hit rate and CDN price per GB to see monthly savings and percent reduction.
Actual bills depend on edge rules, TLS costs, and object size mix; validate against your provider's pricing sheet.
Examples
- 12,000 GB transfer, $0.09/GB origin, 70% hit rate, $0.02/GB CDN ⇒ Baseline cost without CDN: $1,080.00 USD/mo | Modeled cost with CDN: $492.00 USD/mo | Monthly savings from caching: $588.00 USD (54.44%).
- 30,000 GB transfer, $0.12/GB origin, 60% hit rate, $0.03/GB CDN ⇒ Baseline cost without CDN: $3,600.00 USD/mo | Modeled cost with CDN: $1,980.00 USD/mo | Monthly savings from caching: $1,620.00 USD (45.00%).
FAQ
How do I pick a realistic cache hit rate?
Start with 70% for static sites, 40–60% for mixed dynamic traffic, and adjust based on CDN analytics or performance tests.
Does this include CDN request charges?
No. Add per-request costs separately if your CDN charges them, or increase the CDN $/GB input to approximate the blend.
Can I use it for multi-CDN setups?
Yes. Use your aggregate cache hit rate and weighted average CDN pricing to approximate combined performance.
Additional Information
- Assumes all cached traffic is billed at the CDN rate and all misses are billed at your origin egress rate.
- Leaving cache hit rate blank uses 70%, typical for well-tuned static content deployments.
- Savings are calculated on data transfer only; request fees or TLS handshakes are not included.
- Percent savings compare the modeled CDN scenario to paying origin egress for every byte.