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# Math.log2()

The **`Math.log2()`** function returns the base 2 logarithm of a number.

## Syntax

```js
Math.log2(x)
```

### Parameters

- `x`
  - : A number greater than or equal to 0.

### Return value

The base 2 logarithm of `x`. If `x < 0`, returns `NaN`.

## Description

Because `log2()` is a static method of `Math`, you always use it as `Math.log2()`, rather than as a method of a `Math` object you created (`Math` is not a constructor).

This function is the equivalent of `Math.log(x) / Math.log(2)`. For `log2(e)`, use the constant `Math.LOG2E`, which is 1 / `Math.LN2`.
