Peak Bandwidth Calculator
Estimate peak bandwidth demand from average traffic using a peak-to-average factor, for capacity planning.
Inputs
Typical range: 2-3x average for business/office links.
Estimated Peak Bandwidth
125.00Mbps
Headroom Above Average
75.00Mbps
Recommended Link Size (+20%)
150.00Mbps
Step by step
Values used
Average Bandwidth = 50 Mbps; Peak Factor = 2.50
Peak bandwidth
peak = average × peak_factor
Estimated Peak Bandwidth
= 125.00 Mbps
Headroom Above Average
= 75.00 Mbps
Recommended Link Size (+20%)
= 150.00 Mbps
How it works
Network links must be sized for peak demand, not average demand, or they will congest during busy periods. The peak factor captures how much higher traffic spikes above the average during the busiest moments of the day (e.g. lunch-hour video calls, backup windows). Multiplying the average bandwidth by this factor gives the expected peak; adding a further margin (commonly 20%) accounts for growth and unexpected bursts when sizing the actual circuit to purchase.
Formula
Peak bandwidth
peak = average × peak_factor
- \bar{B}
- Average bandwidth
- k
- Peak-to-average factor (typically 2-3)
Frequently Asked Questions
Why is peak bandwidth usually 2-3x the average?
Network usage is bursty and concentrated around specific events — morning login storms, lunchtime streaming, backup jobs, or synchronized video calls — rather than spread evenly across 24 hours. A peak factor of 2-3x is a common empirical benchmark for typical office and campus networks; consumer residential links can spike even higher relative to their daily average.
How do I measure my actual peak factor instead of guessing?
Use SNMP or flow-based monitoring (NetFlow, sFlow) over at least a week to record both the average utilization and the 95th-percentile or maximum 5-minute utilization, then divide peak by average to get your network's actual factor.
Should I provision a link exactly at the peak bandwidth value?
No — provisioning exactly at the calculated peak leaves no room for growth or unexpected bursts. Most network engineers add 15-30% headroom above the calculated peak, which is why this calculator also shows a recommended link size with a 20% margin.