# Python Program to Calculate Value of PI Using Leibniz Formula

The Leibniz formula is an infinite series method of calculating Pi. The formula is a very simple way of calculating Pi, however, it takes a large amount of iterations to produce a low precision value of Pi.

Leibniz formula:
π/4 = 1 - 1/3 + 1/5 - 1/7 + 1/9 - ...
Or, π = 4 ( 1 - 1/3 + 1/5 - 1/7 + 1/9 - ... )

In this python program we first read number of term to consider in series from user and then apply Leibniz formula to caluclate value of Pi.

## Python Source Code: Calculation of Pi using Leibniz Formula

``````
# Calculation of PI using Leibniz formula

# Function to calcultae PI using Leibniz
def leibniz(n):
t_sum = 0
for i in range(n):
term = (-1) ** i /(2*i+1)
t_sum = t_sum + term

return t_sum * 4

# Reading number of terms to be considered in Leibniz formula
terms = int(input("Enter number of terms: "))

# Function call
pi = leibniz(terms)

# Displaying result
print("Pi = ", pi)
``````

## Output

```Enter number of terms: 100000
Pi =  3.1415826535897198
```
To get more accurate result use higher number of terms in series.