# Python | Convert the binary number to decimal without using library function

Binary to decimal in Python: Here, we are going to learn how to convert the given binary number to the decimal number without using any library function in Python?
Submitted by IncludeHelp, on August 09, 2019

Given a binary number and we have to convert it into decimal without using library function.

Example:

```    Input:
1010

Output:
10
```

Python code to convert binary to decimal

```# Python code to convert binary to decimal
def binToDec(bin_value):

# converting binary to decimal
decimal_value = 0
count = 0

while(bin_value != 0):
digit = bin_value % 10
decimal_value = decimal_value + digit * pow(2, count)
bin_value = bin_value//10
count += 1

# returning the result
return decimal_value

# main code
if __name__ == '__main__':
binary = int(input("Enter a binary value: "))
print("decimal of binary ", binary, " is: ", binToDec(binary))

binary = int(input("Enter another binary value: "))
print("decimal of binary ", binary, " is: ", binToDec(binary))

binary = int(input("Enter another binary value: "))
print("decimal of binary ", binary, " is: ", binToDec(binary))
```

Output

```Enter a binary value: 1010
decimal of binary  1010  is:  10
Enter another binary value: 1111000011
decimal of binary  1111000011  is:  963
Enter another binary value: 10000001
decimal of binary  10000001  is:  129
```

Preparation