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Home > Success Center > Network Performance Monitor (NPM) > NPM - Knowledgebase Articles > Calculate the 95th percentile value

Calculate the 95th percentile value

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Created by Karen Valdellon_ret, last modified by Abdul.Aziz on Dec 01, 2016

Views: 4,185 Votes: 1 Revisions: 3

Overview

This article discusses an example in calculating the 95th percentile. 

Environment

All NPM versions

Steps

The calculation of the 95th percentile, a well-known statistical standard used to discard maximum spikes, is based on 5 minute data samples. The calculation gathers these values every 5 minutes for however long you select, throws away the top 5%, yielding the 95th percentile value at the beginning of the list. Consider the following example of how 95th percentile is calculated for a 10 hour work day from 8am to 6pm (600 minutes):

 

Over the 10 hours, the following 120 values were collected for inbound traffic (Mb/s): 
0.149 0.623 0.281 0.136 0.024 0.042 0.097 0.185 0.198 0.243 0.274 0.390 0.971 0.633 0.238 0.142 0.119 0.176 0.131 0.127 0.169 0.223 0.291 0.236 0.124 0.072 0.197 0.105 0.138 0.233 0.374 0.290 0.871 0.433 0.248 0.242 0.169 0.116 0.121 0.427 0.249 0.223 0.231 0.336 0.014 0.442 0.197 0.125 0.108 0.244 0.264 0.190 0.471 0.033 0.228 0.942 0.219 0.076 0.331 0.227 0.849 0.323 0.221 0.196 0.223 0.642 0.197 0.385 0.098 0.263 0.174 0.690 0.571 0.233 0.208 0.242 0.139 0.186 0.331 0.124 0.249 0.643 0.481 0.936 0.124 0.742 0.497 0.085 0.398 0.643 0.074 0.590 0.771 0.833 0.438 0.242 0.092 0.376 0.231 0.627 0.249 0.663 0.181 0.636 0.224 0.342 0.697 0.285 0.108 0.211 0.074 0.490 0.271 0.133 0.338 0.242 0.519 0.376 0.331 0.227 

When reordered from high to low: 
0.971 0.942 0.936 0.871 0.849 0.833 0.771 0.742 0.697 0.690 0.663 0.643 0.643 0.642 0.636 0.633 0.627 0.623 0.590 0.571 0.519 0.497 0.490 0.481 0.471 0.442 0.438 0.433 0.427 0.398 0.390 0.385 0.376 0.376 0.374 0.342 0.338 0.336 0.331 0.331 0.331 0.323 0.291 0.290 0.285 0.281 0.274 0.271 0.264 0.263 0.249 0.249 0.249 0.248 0.244 0.243 0.242 0.242 0.242 0.242 0.238 0.236 0.233 0.233 0.231 0.231 0.228 0.227 0.227 0.224 0.223 0.223 0.223 0.221 0.219 0.211 0.208 0.198 0.197 0.197 0.197 0.196 0.190 0.186 0.185 0.181 0.176 0.174 0.169 0.169 0.149 0.142 0.139 0.138 0.136 0.133 0.131 0.127 0.125 0.124 0.124 0.124 0.121 0.119 0.116 0.108 0.108 0.105 0.098 0.097 0.092 0.085 0.076 0.074 0.074 0.072 0.042 0.033 0.024 0.014 

Drop the first six values, as these equal the top 5% of the values: 
0.771 0.742 0.697 0.690 0.663 0.643 0.643 0.642 0.636 0.633 0.627 0.623 0.590 0.571 0.519 0.497 0.490 0.481 0.471 0.442 0.438 0.433 0.427 0.398 0.390 0.385 0.376 0.376 0.374 0.342 0.338 0.336 0.331 0.331 0.331 0.323 0.291 0.290 0.285 0.281 0.274 0.271 0.264 0.263 0.249 0.249 0.249 0.248 0.244 0.243 0.242 0.242 0.242 0.242 0.238 0.236 0.233 0.233 0.231 0.231 0.228 0.227 0.227 0.224 0.223 0.223 0.223 0.221 0.219 0.211 0.208 0.198 0.197 0.197 0.197 0.196 0.190 0.186 0.185 0.181 0.176 0.174 0.169 0.169 0.149 0.142 0.139 0.138 0.136 0.133 0.131 0.127 0.125 0.124 0.124 0.124 0.121 0.119 0.116 0.108 0.108 0.105 0.098 0.097 0.092 0.085 0.076 0.074 0.074 0.072 0.042 0.033 0.024 0.014 

The 95th percentile is 0.771.

 

To be able to see 95 percentile lines in charts, make sure to enable(is enabled by default) this under Orion Web Console -> Settings -> Web Console Settings -> Chart Settings

 

 

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