How to Convert Binary to Decimal in Python

In this article, we will learn to convert a binary number into a decimal number. Given a binary number, we need to convert the binary number to its equivalent decimal form.

Using loop

def binaryToDecimal(b):
	d , i, n = 0, 0, 0
	while (b != 0):
		dec = b % 10
		d = d + dec * pow(2, i)
		b = b//10
		i += 1
	print(d)

binaryToDecimal(10010)
binaryToDecimal(10110)
binaryToDecimal(10110101001)

Output:

18
22
1449

Using int()

int() will convert the binary number with the base of 2, resulting in a decimal number. While using int(), the binary number must be passed as string. int() can’t convert non-string with explicit base

def binaryToDecimal(b):
	return int(b, 2)

print("Decimal of 10010 is ", binaryToDecimal('10010'))
print("Decimal of 101101 is ", binaryToDecimal('101101'))
print("Decimal of 10110101001 is ", binaryToDecimal('10110101001'))

Output:

Decimal of 10010 is  18
Decimal of 101101 is  45
Decimal of 10110101001 is  1449