What is 90th Percentile Response Time?

The 90th percentile response time value is the value for which 90% of the data points are smaller and 10% are bigger.

To calculate the 90th percentile value:

1.       Sort the transaction instances by their value.

2.       Remove the top 10% instances.

3.       The highest value left is the 90th percentile.

Consider the below example:

There are 10 instances of transaction “TRANSACTION 01” with the values

4 sec 2 sec 3 sec 1 sec 5 sec 17 sec 8 sec 7 sec 6 sec 10 sec



1.       Sort values from best to worst:

1 sec 2 sec 3 sec 4 sec 5 sec 6 sec 7 sec 8 sec 10 sec 17 sec



2.       Remove top 10%, In our case i.e. value “17 sec

1 sec 2 sec 3 sec 4 sec 5 sec 6 sec 7 sec 8 sec 10 sec



3.       The highest value left is the 90th percentile value i.e. “10 sec” is the 90th percentile value.

3 Comments

  1. naved says:

    In loadrunner 11.5 you can also calculate 100% percentile value. Ideally maximum value observed for any tranasaction and 100% percentile value should be same? In case both are coming as different. Please let me know if my assumption is correct?

  2. Troller says:

    Hi,

    I need further information about how 90% is calculated by Loadrunner.
    When we ran a test with 100 users, the 90% response time is 16sec for login & 8 sec for logout.
    But with 1 user, the 90% response time is 18 sec for login & 11 sec for logout.

    Why is this variation in 90% calculation?

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