ClickHouse/docs/en/sql-reference/aggregate-functions/reference/avg.md

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toc_priority: 5
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# avg {#agg_function-avg}
Calculates the arithmetic mean.
**Syntax**
``` sql
avg(x)
```
**Arguments**
- `x` — input values, must be [Integer](../../../sql-reference/data-types/int-uint.md), [Float](../../../sql-reference/data-types/float.md), or [Decimal](../../../sql-reference/data-types/decimal.md).
**Returned value**
- The arithmetic mean, always as [Float64](../../../sql-reference/data-types/float.md).
- `NaN` if the input parameter `x` is empty.
**Example**
Query:
``` sql
SELECT avg(x) FROM values('x Int8', 0, 1, 2, 3, 4, 5);
```
Result:
``` text
┌─avg(x)─┐
│ 2.5 │
└────────┘
```
**Example**
Create a temp table:
Query:
``` sql
CREATE table test (t UInt8) ENGINE = Memory;
```
Get the arithmetic mean:
Query:
```
SELECT avg(t) FROM test;
```
Result:
``` text
┌─avg(x)─┐
│ nan │
└────────┘
```
[Original article](https://clickhouse.com/docs/en/sql-reference/aggregate-functions/reference/avg/) <!--hide-->