elasticsearch/docs/reference/esql/functions/median.asciidoc

[discrete]
[[esql-agg-median]]
=== `MEDIAN`

*Syntax*

[source,esql]
----
MEDIAN(expression)
----

*Parameters*

`expression`::
Expression from which to return the median value.

*Description*

Returns the value that is greater than half of all values and less than half of
all values, also known as the 50% <<esql-agg-percentile>>.

NOTE: Like <<esql-agg-percentile>>, `MEDIAN` is <<esql-agg-percentile-approximate,usually approximate>>.

[WARNING]
====
`MEDIAN` is also {wikipedia}/Nondeterministic_algorithm[non-deterministic].
This means you can get slightly different results using the same data.
====

*Example*

[source.merge.styled,esql]
----
include::{esql-specs}/stats_percentile.csv-spec[tag=median]
----
[%header.monospaced.styled,format=dsv,separator=|]
|===
include::{esql-specs}/stats_percentile.csv-spec[tag=median-result]
|===

The expression can use inline functions. For example, to calculate the median of
the maximum values of a multivalued column, first use `MV_MAX` to get the
maximum value per row, and use the result with the `MEDIAN` function:

[source.merge.styled,esql]
----
include::{esql-specs}/stats_percentile.csv-spec[tag=docsStatsMedianNestedExpression]
----
[%header.monospaced.styled,format=dsv,separator=|]
|===
include::{esql-specs}/stats_percentile.csv-spec[tag=docsStatsMedianNestedExpression-result]
|===