# LOG2

## Syntax

```sql
LOG2(X)
```

## Description

Returns the base-2 logarithm of X.

## Examples

```sql
SELECT LOG2(4398046511104);
+---------------------+
| LOG2(4398046511104) |
+---------------------+
|                  42 |
+---------------------+

SELECT LOG2(65536);
+-------------+
| LOG2(65536) |
+-------------+
|          16 |
+-------------+

SELECT LOG2(-100);
+------------+
| LOG2(-100) |
+------------+
|       NULL |
+------------+
```

<sub>*This page is licensed: GPLv2, originally from*</sub> [<sub>*fill\_help\_tables.sql*</sub>](https://github.com/MariaDB/server/blob/main/scripts/fill_help_tables.sql)

{% @marketo/form formId="4316" %}