It’s usually better to think in percentiles, as they tell you something about a certain percentage of your requests. The most common percentile is the 50th percentile, abbreviated as p50. It’s also known as the median. If the median is 100 ms, half of the requests take longer than 100 ms, and half of the requests take less than 100 ms. Higher percentiles also help you discover outliers, which might be symptoms of something wrong. Typically, the percentiles you’ll want to look at are p90, p95, and p99. The 90th percentile (p90) for the 10 requests above is 3,000 ms, which is an outlier.
