This page is a quick reference checkpoint for PERCENT_RANK in BigQuery: 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.
Computes the percentile rank (from 0 to 1) of each row within the window. Return type is FLOAT64. (As documented)
If this behavior feels unintuitive, the tutorial below explains the underlying pattern step-by-step.
PERCENT_RANK() OVER ([PARTITION BY partition_expression ,...] ORDER BY sort_expression [{ASC|DESC}],...)
SELECT PERCENT_RANK() OVER (PARTITION BY region ORDER BY sales DESC) AS pct_rank_sales FROM sales_table;
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 BigQuery Documentation →Looking for more functions across all SQL dialects? Visit the full SQL Dialects & Window Functions Documentation.