90 Percentile line in JMeter Aggregate Report

The 90% percentile line is where the response time fall under the smallest range of 90% and rest 10% are considered as higher values which are ignored.

Calculate

1. Sort your transactions by response time
2. Remove 10% highest time taking transaction
3. Now the transactions left are your 90 percentile values.

Example

Lets consider we fire 10 threads for a transaction which gives us values as below

Transaction A > 3seconds
Transaction A > 4seconds
Transaction A > 7seconds
Transaction A > 2seconds
Transaction A > 9seconds
Transaction A > 1seconds
Transaction A > 5seconds
Transaction A > 8seconds
Transaction A > 10seconds
Transaction A > 6seconds

Now after sorting the above transaction we get as below

Transaction A > 1 seconds
Transaction A > 2 seconds
Transaction A > 3 seconds
Transaction A > 4 seconds
Transaction A > 5 seconds
Transaction A > 6 seconds
Transaction A > 7 seconds
Transaction A > 8 seconds
Transaction A > 9 seconds
Transaction A > 10 seconds

Now removing the highest 10% value will pop out transaction with 10 seconds

Transaction A > 1 seconds
Transaction A > 2 seconds
Transaction A > 3 seconds
Transaction A > 4 seconds
Transaction A > 5 seconds
Transaction A > 6 seconds
Transaction A > 7 seconds
Transaction A > 8 seconds
Transaction A > 9 seconds

Now the highest value left out is your 90th percentile value as 9 seconds