Calculate 95th percentile bandwidth from sample readings in bps, Kbps, Mbps, or Gbps, using the stated round-up discard-top-5% convention.

Enter equally spaced bandwidth samples. This calculator discards the highest ceil(5% × sample count) readings and returns the highest remaining reading.

Commas, spaces or line breaks separate readings; commas are not thousands separators. Changing the unit reinterprets every number without changing it. At least two readings.

95th Percentile Bandwidth Formula

The calculator sorts equally spaced bandwidth samples, rounds the top-5% sample count upward, discards those readings, and returns the highest remaining value. This preserves the original calculator’s convention; provider rounding and inbound/outbound aggregation rules may differ.

d = ceil(0.05 × n)
i = n - d - 1
P95 = Sáµ¢
Result = P95Mbps / Uâ‚’ut
  • n = total number of numeric bandwidth samples entered
  • d = number of highest samples discarded
  • i = zero-based index of the 95th percentile value after sorting in ascending order
  • Si = sorted bandwidth sample at index i
  • P95 = 95th percentile bandwidth value
  • P95Mbps = 95th percentile value converted to Mbps
  • Uout = output unit conversion factor relative to Mbps

The bandwidth samples field accepts values separated by commas, spaces, or line breaks. The input unit is first converted to Mbps using decimal network units. The samples are then sorted from smallest to largest. The calculator removes the highest ceil(5% of n) samples and reports the largest remaining sample. The result includes equivalent bps, Kbps, Mbps and Gbps values. Changing the sample-unit selector reinterprets the entered numbers; it does not convert them. Commas are list separators, not thousands separators.

Bandwidth Unit Conversion Factors

Unit Meaning Equivalent in Mbps
bps bits per second 0.000001 Mbps
Kbps kilobits per second 0.001 Mbps
Mbps megabits per second 1 Mbps
Gbps gigabits per second 1000 Mbps

Samples Discarded at the 95th Percentile

Number of samples Discarded samples 95th percentile is taken from
10 1 highest sample 9th value in sorted order
20 1 highest sample 19th value in sorted order
100 5 highest samples 95th value in sorted order
288 15 highest samples 273rd value in sorted order

Example Calculations

Example 1: Small Mbps sample set

Suppose you enter these samples in Mbps:

10, 12, 15, 20, 25, 30

There are 6 samples, so the discard count is:

d = ceil(0.05 × 6) = 1

After sorting, the highest sample, 30 Mbps, is discarded. The highest remaining value is 25 Mbps.

95th percentile bandwidth = 25 Mbps

Example 2: Output converted to Gbps

Suppose you enter these samples in Mbps:

800, 850, 900, 950, 1000, 1100, 1300, 2000

There are 8 samples, so the discard count is:

d = ceil(0.05 × 8) = 1

The highest sample, 2000 Mbps, is discarded. The highest remaining value is 1300 Mbps.

1300 Mbps / 1000 = 1.3 Gbps

95th percentile bandwidth = 1.3 Gbps

FAQ

What does 95th percentile bandwidth mean?

95th percentile bandwidth is a way to estimate sustained bandwidth usage while ignoring short traffic spikes. In this method, the top 5% of measured samples are discarded, and the next highest value is used as the result. This is commonly used for bandwidth billing and capacity review.

Why does the calculator discard the highest samples instead of averaging them?

The 95th percentile method is not an average. It is based on sorted samples. By removing the highest 5% of readings, brief spikes have less effect on the result, while regular high usage is still counted.

How many samples should you enter?

You need at least two numeric samples. For a more meaningful 95th percentile result, use samples collected at regular intervals over the period you want to measure, such as every 5 minutes across a day, week, or month.