Python Program to Find Percentage of a Number

To find the percentage in Python, use the formula percentage = (part / total) * 100, for example: percentage = (50 / 200) * 100.

Examples

Inputpart = 50, total = 200

OutputPercentage: 25.0%

Inputpart = 23, total = 50

OutputPercentage: 46.0%

Inputpart = 0, total = 100

OutputPercentage: 0.0%

How to Think About It

To find the percentage, you divide the part value by the total value to get a fraction, then multiply by 100 to convert it to a percentage. This is like finding how much of a whole something is, expressed out of 100.

Algorithm

1

Get the part value (the portion you want to find the percentage of).

2

Get the total value (the whole or maximum possible value).

3

Divide the part by the total to get a decimal fraction.

4

Multiply the result by 100 to convert it to a percentage.

5

Display or return the percentage value.

Code

python

part = float(input('Enter the part value: '))
total = float(input('Enter the total value: '))
percentage = (part / total) * 100
print(f'Percentage: {percentage}%')

Output

Enter the part value: 50
Enter the total value: 200
Percentage: 25.0%

Dry Run

Let's trace the example where part = 50 and total = 200 through the code.

1

Input part value

User inputs 50, so part = 50.0

2

Input total value

User inputs 200, so total = 200.0

3

Calculate percentage

percentage = (50.0 / 200.0) * 100 = 0.25 * 100 = 25.0

4

Print result

Output is 'Percentage: 25.0%'

Step	part	total	percentage	Output
1	50.0	-	-	-
2	50.0	200.0	-	-
3	50.0	200.0	25.0	-
4	50.0	200.0	25.0	Percentage: 25.0%

Why This Works

Step 1: Divide part by total

Dividing part by total gives the fraction of the whole that the part represents.

Step 2: Multiply by 100

Multiplying the fraction by 100 converts it to a percentage, which is out of 100.

Step 3: Display the result

Printing the result shows the percentage value clearly to the user.

Alternative Approaches

Using a function

python

def find_percentage(part, total):
    return (part / total) * 100

print(f'Percentage: {find_percentage(50, 200)}%')

This approach makes the code reusable for different inputs.

Using integer inputs and rounding

python

part = int(input('Enter part: '))
total = int(input('Enter total: '))
percentage = round((part / total) * 100, 2)
print(f'Percentage: {percentage}%')

Rounding limits decimal places for cleaner output.

Complexity: O(1) time, O(1) space

Time Complexity

The calculation involves only basic arithmetic operations without loops, so it runs in constant time O(1).

Space Complexity

Only a few variables are used to store inputs and the result, so space complexity is O(1).

Which Approach is Fastest?

All approaches perform the same constant-time calculation; using a function adds readability but no significant overhead.

Approach	Time	Space	Best For
Direct calculation	O(1)	O(1)	Simple scripts
Function-based	O(1)	O(1)	Reusable code
Rounded output	O(1)	O(1)	Cleaner display