This page is a quick reference checkpoint for NTILE in BigQuery: behavior, syntax rules, edge cases, and a minimal example; plus the official vendor documentation.
NTILE divides the rows into a specified number of buckets and assigns each row a bucket number.
Assigns each row to one of bucket_count quantile buckets (1-based) within the window. The function returns an INT64 value. ([docs] page)
If this behavior feels unintuitive, the tutorial below explains the underlying pattern step-by-step.
NTILE(bucket_count) OVER (window_clause)
SELECT region, amount, NTILE(4) OVER (PARTITION BY region ORDER BY amount DESC) AS quartile FROM sales;
If you came here to confirm syntax, you’re done. If you came here to get better at window functions, choose your next step.
NTILE 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.