W Code - Pattern-Based DSA Learning Platform

Bhanu Bisht

Convert binary numbers to decimal. Essential for bit manipulation interview problems. Whether you're solving coding interview problems or studying for exams, understanding how to convert binary to decimal is essential.

Conversion Logic:

Multiply each bit by 2^position (right to left, starting from 0) and sum all values.

This is a fundamental skill tested in coding interviews, competitive programming, and CS theory exams.

Example 1

Input: 1010

Output: 10

Explanation: 1×2³ + 0×2² + 1×2¹ + 0×2⁰ = 8 + 0 + 2 + 0 = 10

Example 2

Input: 11111111

Output: 255

Explanation: Sum of 2⁰ through 2⁷ = 255 (8-bit max)

Example 3

Input: 100000

Output: 32

Explanation: 1×2⁵ = 32

Test your understanding with these exercises:

1.Convert 5 different values using the method above

2.Implement the conversion algorithm in your preferred language

3.Solve related problems on W Code to build speed

Interview tip: Be ready to explain the conversion process step-by-step on a whiteboard.

python
def binary_to_decimal(binary_str: str) -> int:
    result = 0
    for bit in binary_str:
        result = result * 2 + int(bit)
    return result

# Or simply: int(binary_str, 2)

Multiply each bit by 2^position (right to left, starting from 0) and sum all values.

Yes, number system conversions are common in aptitude rounds and bit manipulation problems.

Related: decimal-to-binary, binary-to-hex, octal-to-decimal. Understanding these together builds a complete foundation.

Conversion Logic:

Multiply each bit by 2^position (right to left, starting from 0) and sum all values.

This is a fundamental skill tested in coding interviews, competitive programming, and CS theory exams.

Example 1

Input: 1010

Output: 10

Explanation: 1×2³ + 0×2² + 1×2¹ + 0×2⁰ = 8 + 0 + 2 + 0 = 10

Example 2

Input: 11111111

Output: 255

Explanation: Sum of 2⁰ through 2⁷ = 255 (8-bit max)

Example 3

Input: 100000

Output: 32

Explanation: 1×2⁵ = 32

Test your understanding with these exercises:

1.Convert 5 different values using the method above

2.Implement the conversion algorithm in your preferred language

3.Solve related problems on W Code to build speed

Interview tip: Be ready to explain the conversion process step-by-step on a whiteboard.

python
def binary_to_decimal(binary_str: str) -> int:
    result = 0
    for bit in binary_str:
        result = result * 2 + int(bit)
    return result

# Or simply: int(binary_str, 2)

Multiply each bit by 2^position (right to left, starting from 0) and sum all values.

Yes, number system conversions are common in aptitude rounds and bit manipulation problems.

Related: decimal-to-binary, binary-to-hex, octal-to-decimal. Understanding these together builds a complete foundation.

Binary to Decimal Converter

How It Works

Step-by-Step Examples

Example 1

Example 2

Example 3

Practice Problems

Implementation Code

Frequently Asked Questions

Binary to Decimal Converter

How It Works

Step-by-Step Examples

Example 1

Example 2

Example 3

Practice Problems

Implementation Code

Frequently Asked Questions

Binary to Decimal Converter

How It Works

Step-by-Step Examples

Example 1

Example 2

Example 3

Practice Problems

Implementation Code

Related Converters

Frequently Asked Questions

Binary to Decimal Converter

How It Works

Step-by-Step Examples

Example 1

Example 2

Example 3

Practice Problems

Implementation Code

Related Converters

Frequently Asked Questions