Binary ⇔ Decimal Converter

Instantly convert between binary (base-2) and decimal (base-10) systems and see the detailed calculation.

Calculation Breakdown

Enter a number in either box to see the conversion and a step-by-step explanation here.

The Complete Guide to Binary and Decimal Conversion

Quick Summary: Our free online binary to decimal converter instantly transforms binary numbers (base-2) to decimal (base-10) and vice versa. Get detailed step-by-step explanations and master number system conversions for programming, computer science, and electronics.

At the core of every digital device lies a language of just two digits: 0 and 1. This is the binary system, the fundamental language that powers all computing technology. While computers operate in binary, humans naturally work with the decimal system using ten digits (0-9). The ability to seamlessly translate between these two number systems is essential for programmers, computer scientists, electronics engineers, and anyone working with digital technology. Our powerful binary to decimal converter not only provides instant conversions but also teaches you the underlying process with comprehensive, step-by-step explanations.

Understanding Binary and Decimal Number Systems

01

Binary System (Base-2)

Uses only two digits: 0 and 1. Each digit position represents a power of 2. This is the native language of computers and digital electronics.

0-9

Decimal System (Base-10)

Uses ten digits: 0 through 9. Each digit position represents a power of 10. This is the standard number system used in daily life and mathematics.

Historical Evolution of Number Systems

From Ancient Mathematics to Modern Computing

Decimal System Origins

The decimal system traces back to ancient Indian mathematics around the 1st to 4th centuries, with the revolutionary Hindu-Arabic numeral system that introduced zero and positional notation. The use of ten digits likely originated from counting on ten fingers.

Binary System Development

While binary concepts appeared in ancient Indian texts, German mathematician Gottfried Wilhelm Leibniz formalized the modern binary system in the 17th century. He saw philosophical significance in the system, but its practical application only emerged with 20th-century electronic computers.

How to Convert Binary to Decimal: Step-by-Step Guide

💡 Conversion Formula

Binary Value = (digit × 2position) + (digit × 2position) + ...

Let's convert the binary number 101101 to decimal using the positional notation method:

Step Process Calculation
1 Write binary number with positions 1 0 1 1 0 1
5 4 3 2 1 0
2 Calculate powers of 2 for each position 2⁵=32, 2⁴=16, 2³=8, 2²=4, 2¹=2, 2⁰=1
3 Multiply each digit by its power value (1×32) + (0×16) + (1×8) + (1×4) + (0×2) + (1×1)
4 Sum the results 32 + 0 + 8 + 4 + 0 + 1 = 45

How to Convert Decimal to Binary: Step-by-Step Guide

💡 Division Method

Repeatedly divide by 2 and track remainders from bottom to top

Let's convert the decimal number 45 back to binary using the division method:

Division Process

45 ÷ 2 = 22 Remainder 1
22 ÷ 2 = 11 Remainder 0
11 ÷ 2 = 5 Remainder 1
5 ÷ 2 = 2 Remainder 1
2 ÷ 2 = 1 Remainder 0
1 ÷ 2 = 0 Remainder 1

Reading the Result

Read remainders from bottom to top:

1 0 1 1 0 1

Thus, decimal 45 = binary 101101

Common Number Systems in Computing

2

Binary (Base-2)

Digits: 0, 1
Machine language, digital circuits

8

Octal (Base-8)

Digits: 0-7
Unix permissions, shorthand for binary

16

Hexadecimal (Base-16)

Digits: 0-9, A-F
Memory addresses, color codes, programming

Data Measurement Hierarchy

From Bits to Terabytes

Bit
0 or 1
Byte
8 bits
Kilobyte
1,024 bytes
Megabyte
1,024 KB

Frequently Asked Questions

Is this binary to decimal converter completely free?

Yes, our binary to decimal converter is 100% free and works entirely in your browser. No registration required, and your data never leaves your computer.

What's the largest number I can convert?

Our converter handles integers up to about 9 quadrillion (2⁵³ - 1) with perfect precision, which covers virtually all practical applications in programming and computer science.

What does "base-2" and "base-10" mean?

The "base" indicates how many unique digits a number system uses. Base-2 (binary) uses two digits (0,1), while base-10 (decimal) uses ten digits (0-9). The base determines the value of each position in a number.

How are letters converted to binary?

Letters and symbols use character encoding standards like ASCII and Unicode. Each character gets a unique decimal number, which is then converted to binary. For example, 'A' is decimal 65, which is 01000001 in binary.

Ready to Master Binary Conversion?

From simple conversions to complex calculations, our free binary to decimal converter provides instant results with detailed explanations. Perfect for students, developers, and tech professionals.

Conclusion: Your Gateway to Digital Literacy

Understanding the relationship between binary and decimal systems is fundamental to digital literacy in our technology-driven world. Our binary to decimal converter serves as both a practical tool and an educational resource, designed to make number system conversions accessible and understandable for everyone.

With real-time bidirectional conversion, comprehensive step-by-step explanations, and support for large numbers, this tool is indispensable for programming students, software developers, electronics engineers, and technology enthusiasts. Whether you're debugging code, studying computer architecture, or simply curious about how computers work, our converter provides the clarity and precision you need.

Bookmark this page and transform the way you work with number systems. The bridge between human thinking and machine language is now at your fingertips.