Calculator Inputs
Example Data Table
Sample scenarios help you sanity-check input ranges.
| Scenario | Transfer (GB) | Offload (%) | Model | Key rate | Estimated monthly total |
|---|---|---|---|---|---|
| Small office | 450 | 5 | Per GB | $0.08 / GB | $95–$140 |
| Streaming startup | 12,000 | 35 | Per GB | $0.05 / GB | $450–$900 |
| Enterprise edge link | 8,500 | 10 | 95th | $2.75 / Mbps | $650–$1,250 |
Formula Used
1) Effective Transfer
Effective GB = Transfer GB × (1 − Offload%) × (Billable%).
2) Volume-based Billing
Overage GB = max(0, Effective GB − Included GB).
Usage charge = Overage GB × Rate per GB × Regional multiplier.
Subtotal = (Base fee × Regional multiplier) + Add-ons + Usage charge.
3) 95th Percentile Billing
If you estimate, Average Mbps = bits transferred ÷ seconds ÷ 1,000,000.
Then 95th Mbps ≈ Average Mbps × Peak factor (optionally capped).
Commit cost = Commit Mbps × Commit rate × Regional multiplier.
Overage cost = max(0, 95th − Commit) × Overage rate × Regional multiplier.
4) Discounts and Tax
Discount = Subtotal × Discount%.
Tax = (Subtotal − Discount) × Tax%.
Total = Subtotal − Discount + Tax.
How to Use This Calculator
- Choose the pricing model that matches your invoice.
- Enter monthly transfer and optional CDN offload percent.
- Set billable portion to reflect charged traffic.
- Fill plan-specific rates, then add discounts and tax.
- Press Calculate to show results above the form.
- Use Download CSV or Download PDF for sharing.
Bandwidth demand and cost drivers
Monthly transfer grows with video delivery, updates, backups, images, and APIs. A 1,200 GiB month over 30 days averages about 3.97 Mbps, but traffic rarely stays flat. Launches, patch days, and peak viewing windows can compress a large share of bytes into short periods, increasing billed capacity under percentile contracts.
Volume pricing: predictable, but sensitive to overage
Volume plans combine a base fee, included transfer, and an overage rate. Using the default inputs, 1,200 GB with 10% offload becomes 1,080 effective GB. With 1,000 GB included and $0.09 overage, the usage charge is $7.20. Adding a $79 base fee and $25 add‑ons yields a $111.20 subtotal; a 5% discount reduces it to $105.64 before tax.
Percentile pricing: translating variability into billable Mbps
Percentile billing typically discards the top 5% of measured intervals, then bills the remaining peak rate. If you estimate from transfer, the calculator multiplies average Mbps by a peak factor. With 3.97 Mbps average and a 2.20 factor, the estimate is about 8.73 Mbps. Entering your measured 95th value aligns estimates with provider portals and avoids guessing.
Financial levers that don’t harm performance
Offload and billable percentage represent practical optimizations: caching, compression, image resizing, and smarter routing. Every 10% offload reduces effective GB by 10%, lowering per‑GB charges and reducing the average Mbps used for estimates. Regional multipliers help compare markets. Discounts apply before tax, so negotiated terms compound across base, commit, and overage components.
Operational use: budgeting, vendor comparison, and audit trails
Run scenarios with consistent days, tax, and add‑ons, then swap only the plan rates to compare suppliers. Track “cost per effective GB” to normalize spend as traffic mix changes. Export CSV for procurement sheets and forecasting models, and export PDF for approvals, audits, and month‑end variance reviews. If committed Mbps is far above your 95th, right‑sizing the commit can reduce recurring costs. For planning, add 10–20% headroom to cover seasonality, then validate with real monitoring reports each month quarterly too.
FAQs
What is “effective transfer” in this calculator?
It is transfer after CDN offload and the billable portion are applied. This approximates the traffic your provider actually charges, not the raw bytes you serve.
When should I choose volume pricing?
Choose it when invoices are primarily per‑GB with a base fee and included usage. It works well for steady workloads and is easy to forecast when growth is linear.
When is 95th percentile pricing more appropriate?
Use it when your contract bills committed Mbps plus overage above commit. It is common for dedicated links and helps translate bursty traffic into capacity and cost.
How do I set the peak factor?
Start with 2.0 to 2.5 for moderately bursty services. If traffic is highly event‑driven, test 3.0+. If you have provider reports, prefer the measured 95th option.
Why do discounts show as a negative line item?
Discounts reduce the subtotal, so they appear below zero to make the breakdown sum correctly. The chart keeps that sign so you can see how much the contract saves.
Does the PDF export match my provider’s invoice exactly?
It matches the calculator’s assumptions and rounding, but providers may apply minimums, tiered rates, or different rounding rules. Use exports for planning and comparison, then reconcile with the invoice.