The 90th percentile is the value for which 90% of the data points are smaller

The 90th percentile is a measure of statistical distribution, not unlike the median. The median is the middle value. The median is the value for which 50% of the values were bigger, and 50% smaller. The 90th percentile tells you the value for which 90% of the data points are smaller and 10% are bigger.

Statistically, 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.

**Example:**

There are ten instances of transaction "t1" with the values 1,3,2,4,5,20,7,8,9,6 (in sec).

1. Sort by value — 1,2,3,4,5,6,7,8,9,20.

2. Remove top 10 % — remove the value "20."

3. The highest value left is the 90th percentile — 9 is the 90th percentile value.

The 90th percentile value answers the question, "What percentage of my transactions have a response time less than or equal to the 90th percentile value?" Given the above information, here is how LoadRunner calculates the 90th percentile.

**In Analysis 6.5:**

The values for the transaction are ordered in a list.

The 90% is taken from the ordered list of values. The place from which it is taken is

Rounding to the small value the number: 0.9 * (Number of Values – 1) + 1

**In Analysis 7 and above:**

Each value is counted in a range of values. For example, 5 can be counted in a range of 4.95 to 5.05, 7.2 in a range of 7.15 to 7.25. The 90% is taken from the range of values that the number of transaction in it and before it is >= ( 0.9 * Number of Values).

This difference in the methods can lead to different 90% values. Again, both methods lead to correct values as defined by the 90th percentile. However, the algorithm to calculate these figures has changed in LoadRunner 7 and above.

### Like this:

Like Loading...

*Related*

good explaination. thanks.

Thanks for explaining this. What business question does a 90th percentile report answer? It seems like it is a filter to be added to reports on transaction times, step times, and latency measurements. Like I just need to strip out the 10% worst performers to see where is the majority (90%) of the transaction performance. How does 90th percentile help?

-Frank

why 90th only?why not 85 or 95?

Why 90th only?? Not 75 or 95???

Thanks for your publication. I would love to say that the very first thing you will need to conduct is check if you really need credit restoration. To do that you have got to get your hands on a copy of your credit file. That should never be difficult, because the government mandates that you are allowed to be issued one no cost copy of your actual credit report annually. You just have to ask the right individuals. You can either look into the website with the Federal Trade Commission or contact one of the main credit agencies straight.

Very Helpful!

Nice..Really helpful..!!

Nice Writeup .

Thanks for this post its very helpful for me…

it is very informative and simple to follow