Finds the median or another percentile — the value below which a given share of the data lies.
PERCENTILE_CONT(<fraction>) WITHIN GROUP (ORDER BY <expression>)
PERCENTILE_CONT(0.5) is the median: half the values are smaller, half are larger. Unlike the average, a single very large value doesn't shift it. The function can return a number between two existing ones; if you need exactly one of the existing values, use PERCENTILE_DISC.
employees
| name | department | salary | bonus | phone |
|---|---|---|---|---|
| Emma | backend | 1200 | 300 | +44 7700 900123 |
| Liam | backend | 1000 | NULL | NULL |
| Olivia | frontend | 1350 | 150 | +44 7700 900456 |
| Noah | frontend | 950 | NULL | +44 7700 900789 |
| Sophia | design | 1200 | 200 | NULL |
orders
| id | created_at | amount |
|---|---|---|
| 1 | 2026-07-03 10:15:00 | 120.50 |
| 2 | 2026-07-28 18:40:00 | 80.25 |
| 3 | 2026-08-09 09:05:00 | 199.99 |
| 4 | 2026-08-21 14:30:00 | 45.00 |
| 5 | 2026-09-02 11:00:00 | 64.75 |
These tables already exist in the sandbox — the examples below use them. Want to try this in your own database? Copy the SQL.
| median_salary |
|---|
| 1200 |
| median | average |
|---|---|
| 80.25 | 102.10 |
The 199.99 order pulls the average up, while the median stays a “typical” amount.
| quartiles |
|---|
| [1000,1200,1200] |
An array of fractions gives an array of answers: for a quarter, a half and three quarters.
The syntax is unusual: the fraction goes in the function's brackets, and the column in WITHIN GROUP (ORDER BY …). PERCENTILE_CONT(salary, 0.5) throws WITHIN GROUP is required for ordered-set aggregate.
The fraction runs from 0 to 1, not in percent: the 90th percentile is 0.9, and 90 throws percentile value 90 is not between 0 and 1.
PERCENTILE_CONT only works with numbers and intervals — for dates and text, use PERCENTILE_DISC. And it can't be a window function with OVER: OVER is not supported for ordered-set aggregate.