How 90th Percentile Is Calculated in Reports

Recommended guidance
The 90th percentile is the value below which 90% of measured samples fall. In AIQ reporting, use it to understand typical high-end response time without letting a few extreme outliers dominate the interpretation.
How to interpret it
If the 90th percentile response time is 2 seconds, 90% of samples completed in 2 seconds or less.
The remaining 10% were slower than that value.
Percentiles should be reviewed with average, median, error rate, throughput, and sample count.
Small sample sizes can make percentile values unstable.
Reporting checklist
Confirm the metric and transaction represented by the percentile.
Check whether failed or timed-out samples are included or excluded.
Compare percentile values only between runs with similar data, load, and environment.
Use percentiles with charts and logs to identify sustained slowness versus isolated spikes.
Last updated: October 6, 2026