PostgreSQL 18 reference · Math Functions

PostgreSQL SQRT() Function

Return the square root of a number, so sqrt(16) is 4. Negative input raises an error; cbrt() gives the cube root.

PostgreSQL 18

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Syntax

sqrt(x)  |  cbrt(x)

Parameter	Description
`x`	A number (`integer`, `numeric` or `double precision`).

double precision or numeric.

Roots

SELECT sqrt(16) AS a, sqrt(2::numeric) AS b, cbrt(64) AS cube_root;

Output

 a |         b         | cube_root
---+-------------------+-----------
 4 | 1.414213562373095 |         4
(1 row)

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Distance between two points

SELECT sqrt(power(3, 2) + power(4, 2)) AS distance;

Output

 distance
----------
        5
(1 row)

Run this on your computer — see “Get Started” for setup.

POWER() · Raise a number to a power, so power(2, 10) is 1024. pow() is another name for the same function.
SQL Aggregate Functions · tutorial