# math.log2() method with example in Python

Python math.log2() method: Here, we are going to learn about the math.log2() method with example in Python.
Submitted by IncludeHelp, on April 20, 2019

## Python math.log2() method

math.log2() method is a library method of math module, it is used to get the base-2 logarithm of a number, it accepts a number and returns base-2 logarithm of the given number.

The method math.log2() gives more accurate result than the log(x, 2).

Note: If we provide anything else except a number, the method returns a TypeError – "TypeError: a float is required".

Syntax of math.log2() method:

```    math.log2(x)
```

Parameter(s):x – is the number whose base-2 logarithm to be calculated.

Return value: float – it returns a float value that is the base-2 logarithm of the number x.

Example:

```    Input:
x = 21

# function call
print(math.log2(x))

Output:
4.392317422778761
```

### Python code to demonstrate example of math.log2() method

```# python code to demonstrate example of
# math.log2() method

# importing math module
import math

# Base-2 logarithm
x = 21
print("Base-2 logarithm of ", x, " is = ", math.log2(x))

x = 10.23
print("Base-2 logarithm of ", x, " is = ", math.log2(x))
```

Output

```Base-2 logarithm of  21  is =  4.392317422778761
Base-2 logarithm of  10.23  is =  3.354734239970604
```