Python Program for Binary To Decimal Conversion

Binary to Decimal Conversion

In this article we will discuss binary to decimal conversion in Python. For this purpose we need to take a binary integer number from user and convert that binary integer number to its decimal equivalent form and then print the converted number on to the screen. A Decimal number can be calculated by multiplying every digits of binary number with 2 to the power of the integers starts from 0 to n-1 where n refers as the total number of digits present in a binary number and finally add all of them.

Binary to decimal conversion

Working :

 A Decimal number can be calculated by multiplying every digits of binary number with 2 to the power of the integers

 starts from 0 to n-1 where n refers as the total number of digits present in a binary number and finally add all of them.

Methods Discussed :

  1. Algorithmic way (Binary to Decimal)
  2. Inbuilt Method (Binary to Decimal)

Method 1

Algorithm :

  • While num is greater then zero
  • Store the unit place value of num to a variable (rem)
  • Calculate rem with base and add it to answer
  • Completely divide Num by 10 and multiply base with 2

Time and Space Complexities

  • Time Complexity – O(N), where N is the count of the digits in the binary number
  • Space Complexity – O(1), Constant Space

Python Code :

Run
num = 10
binary_val = num
decimal_val = 0
base = 1

while num > 0:
    rem = num % 10
    decimal_val = decimal_val + rem * base
    num = num // 10
    base = base * 2

print("Binary Number is {}\nDecimal Number is {}".format(binary_val, decimal_val))

Output :

Binary Number is 10
Decimal Number is 2

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20 comments on “Python Program for Binary To Decimal Conversion”


  • Nachiket

    bin=’10001′
    sum=0
    n=len(bin)-1
    for i in range(n,-1,-1):
    sum=sum+(int(bin[i])*pow(2,i))
    print(sum)


  • Mathavan

    ls=[]
    for i in str(n):
    ls.append(i)
    k=len(ls)-1
    g=0
    i=0
    while(i<len(ls)):
    if(ls[i]=="1"):
    g+=2**k k-=1
    i+=1 print(g)


  • D

    n=input()
    s=0
    k=len(n)
    d=(2**(k-1))
    for i in (n):
    s=s+(int(i)*d)
    k-=1
    print(n,”decimal form is”,s)


  • Palak

    n = int(input())
    le = len(str(n))
    dec = 0
    l = le-1

    for i in str(n):
    dec = dec + (int(i)*(pow(2 , l)))
    l = l-1

    print(dec)


  • Saurabh

    def binary_to_deci(n):
    decimal =0
    n1 =str(n)
    for i in range(0,len(n1)):
    decimal+= (int(n1[i])*pow(2,len(n1)-1-i))
    return decimal

    n= 1001
    print(“Deciaml value of {} is”.format(n),binary_to_deci(n))


  • cherith

    n=int(input())
    l=list(str(n))
    print(l)
    l.reverse()
    print(l)
    decimal=0
    for i in range(0,len(l)):
    decimal+=int(l[i])*(2**i)

    print(decimal)


  • Asazad

    n=int(input())
    ls=[]
    for i in str(n):
    ls.append(i)
    k=len(ls)-1
    g=0
    i=0
    while(i<len(ls)):
    if(ls[i]=="1"):
    g+=2**k

    k-=1
    i+=1

    print(g)