How to use this calculator
- Enter the current monthly CDN transfer and request volume.
- Use the effective prices from your bill or contract.
- Set the expected monthly growth and forecast length.
- Review cumulative spend and the ending monthly run rate.
#1821 · Startup & SaaS Tool
CDN Traffic Cost Forecast Calculator
Forecast monthly CDN traffic cost from starting data transfer, request volume, growth, and provider pricing, with a cumulative projection and ending-month estimate.
Calculator
Traffic, growth, and ratesFormula
Month m traffic = Starting traffic × (1 + growth)m−1
Monthly cost = TB × 1,000 × transfer rate + requests (millions) × request rate
Monthly cost = TB × 1,000 × transfer rate + requests (millions) × request rate
What the result means
The main result is total estimated CDN spend across the selected period. The ending monthly cost shows the new run rate if traffic compounds at the entered rate.
This model uses decimal units (1 TB = 1,000 GB) and a constant price. Free tiers, regional bands, cache-fill traffic, taxes, and tiered discounts are not included unless reflected in your entered rates.
Example calculation
With 50 TB, 500 million requests, $0.06/GB, $0.75 per million requests, 8% monthly growth, and 12 months, month-one cost is $3,375.00. The 12-month cumulative forecast is $64,047.80, and month 12 reaches $7,869.28.
Tips for better results
- Use billing-export data rather than rounded dashboard totals.
- Keep traffic volume and pricing units aligned before comparing scenarios.
- Recalculate after a contract, architecture, or retention-policy change.
- Run separate forecasts for regions with materially different transfer prices.
- Test a lower-growth case to establish a budget range.
Frequently asked questions
Does the CDN forecast include tiered transfer pricing?
No. It applies one effective transfer rate to all forecast traffic; enter a blended rate if your bill uses tiers.
How are requests projected in this CDN cost forecast?
Request volume grows at the same monthly percentage as data transfer.
Can monthly CDN traffic growth be negative?
Yes. A rate above −100% models declining traffic while keeping projected volume nonnegative.
Does the calculator use 1,024 GB per TB?
No. It uses decimal billing units of 1,000 GB per TB.
Are origin egress and cache-fill charges included?
Only if you incorporate them into the effective rates you enter.
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Variables and units
| Variable | Meaning | Unit |
|---|---|---|
| T₁ | Starting monthly transfer | TB |
| R₁ | Starting request count | millions |
| g | Monthly growth rate | % |
| m | Forecast month | month |