The CDN Traffic Capacity Needs Estimator projects the delivery capacity required to support expected traffic growth and a chosen peak-load factor, then adds operational headroom. It is intended for teams that plan bandwidth, committed CDN capacity, edge delivery limits, or internal traffic budgets and need to turn average traffic into a higher peak-oriented requirement.
The model starts with current average throughput, increases it by the expected growth rate, multiplies that value by a peak factor, and finally adds a headroom percentage. This produces a target throughput figure in Gbps. A peak factor greater than 1 represents the difference between average and busy-period traffic; for example, 2.0 means the modeled peak is twice the projected average. The result is a planning estimate rather than a network guarantee because real capacity needs also depend on geography, cache efficiency, traffic shape, failover design, and provider-specific delivery limits.
Traffic capacity assumptions
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Gbps
Result
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Target CDN delivery capacity
Projected average—
Modeled peak—
Additional capacity needed—
Capacity change—
1. Enter current average throughput Use a representative average delivery rate in Gbps.
2. Project traffic growth Enter the expected percentage increase over the planning horizon.
3. Set the peak factor Use the ratio of busy-period throughput to average throughput; a value of 2 means peak traffic is twice average.
4. Add operational headroom Reserve extra capacity above the modeled peak for uncertainty, incidents, and short spikes.
5. Enter current capacity Provide the delivery capacity you already have available in Gbps.
6. Review the capacity gap Compare the target with current capacity to estimate how much additional delivery capacity may be required.
Formula: Projected Average = Current Average Throughput × (1 + Traffic Growth) Modeled Peak = Projected Average × Peak-to-Average Factor Target Capacity = Modeled Peak × (1 + Headroom Rate) Additional Capacity = max(Target Capacity − Current Capacity, 0)
Throughput values are expressed in Gbps. Traffic Growth and Headroom are percentages converted to decimals. The peak factor is a direct multiplier and must be at least 1. The estimate assumes these relationships remain stable across the planning scenario.
What the result means
The main result is the delivery throughput needed to cover projected average growth, the selected peak factor, and operational headroom.
Use measured peak patterns and provider-specific architecture data to validate the scenario before making a capacity commitment.
Given: 8 Gbps current average throughput, 30% traffic growth, a 2.0 peak factor, 20% headroom, and 25 Gbps current capacity.
Result: The modeled target is about 24.96 Gbps, so the current 25 Gbps capacity narrowly covers this scenario.
How do I choose a peak-to-average factor?
Derive it from historical traffic if possible by dividing a representative busy-period throughput by the corresponding average. Avoid using an arbitrary factor when you have time-series data available.
Why is the minimum peak factor 1?
A factor below 1 would imply modeled peak throughput is lower than average throughput, which is not consistent with the intended definition.
Should growth be monthly or annual?
Enter the total growth expected over the planning horizon represented by your current-versus-future comparison. The calculator applies the percentage once; it does not compound growth by month.
Does headroom duplicate the peak factor?
No. The peak factor converts average throughput to an expected busy-period level, while headroom adds a buffer above that modeled peak.
What if my current capacity already exceeds the target?
Additional capacity needed will show zero. The target and capacity-change values can still help you evaluate how much margin remains under the scenario.