What is the 95th percentile?

The 95th percentile is the value below which 95% of all observations in a dataset fall. In simpler terms, if you order the data in ascending order, the 95th percentile is the number that separates the lower 95% of the data from the upper 5%.

For example, if measuring server response time, and the 95th percentile is 200 ms, it means that 95% of requests are processed in 200 ms or less, and the remaining 5% take longer.

This is a useful metric for assessing performance and identifying rare but important cases.