# time.perf_counter() function in Python with examples

In this tutorial, we will learn about time.perf_counter() function in Python. Its function is to calculate the total execution time of any program.

It returns a float value (precise value of execution time).

It is helpful in comparing any two algorithms or checking if it is done under a given time. It also has many applications in various fields.

## Calculating the execution time of a basic program

Creating an introductory program for printing the execution time as-

```import time
print(time.perf_counter())```

Output:

`18807.00947833`

This is how we tried to print the execution time using `time.perf_counter()`.

## Calculating the execution time of Hello World

We will print and see what the execution time of this program is. Let’s move forward to the snippet part as-

```import time
print("Hello World")
print(time.perf_counter())```

Output:

```Hello World
5266.26077137```

## Calculate the execution time of a sum of two numbers

We will calculate the sum of two numbers and then print the execution time. Let’s try to print the execution time of this program-

```import time
a=9
b=10
c=0
c=a+b
print(c)
print(time.perf_counter())```

Output:

```19
2722.151702753```

Calculate the execution time of the reverse of a number

We will reverse a number using the below algorithm and calculate its execution time-

```import time
num = 1234
temp = num
rev = 0
while num > 0:
remainder = num % 10
rev = (rev * 10) + remainder
num = num // 10

print(rev)
print(time.perf_counter())```

Output:

```4321
48953.407851554```

This tutorial has a lot of information on this particular module to calculate the execution time. I hope you found this tutorial helpful. Thanks for reading!