This page is a quick reference checkpoint for PERCENT_RANK in MySQL: behavior, syntax rules, edge cases, and a minimal example; plus the official vendor documentation.
PERCENT_RANK returns a row's relative rank as a percentage between 0 and 1.
Returns (rank - 1) / (rows_in_partition − 1); the first row has 0 and the last has 1.
If this behavior feels unintuitive, the tutorial below explains the underlying pattern step-by-step.
PERCENT_RANK() must be used with an OVER clause and computes the relative rank of a row within its partition.
SELECT PERCENT_RANK() OVER (ORDER BY salary) AS pct_rank FROM employees;
If you came here to confirm syntax, you’re done. If you came here to get better at window functions, choose your next step.
PERCENT_RANK is part of a bigger window-function pattern. If you want the “why”, start here: Percentile Distribution
Reading docs is useful. Writing the query correctly under pressure is the skill.
For the authoritative spec, use the vendor docs. This page is the fast “sanity check”.
View MySQL Documentation →Looking for more functions across all SQL dialects? Visit the full SQL Dialects & Window Functions Documentation.