Decimal to Binary Converter - Convert Numbers to Binary Code

Decimal to Binary Converter - Free Online Tool

Convert Any Decimal Number to Binary Instantly

Our free decimal to binary converter helps you change regular numbers (decimal) into computer language (binary). Just type any number from 0 to 65,535 and get the binary result immediately. Perfect for students, programmers, and anyone learning about computer numbers.

This tool shows you step-by-step how the conversion works, so you can learn while you convert. No registration needed - completely free to use!

What You Get:

  • Instant decimal to binary conversion
  • Step-by-step conversion process
  • Binary, octal, and hexadecimal results
  • Verification calculations
  • Educational examples and explanations
  • Mobile-friendly design
  • Print and download options

Why Use Our Decimal to Binary Converter?

Easy to Use

Simple interface that anyone can understand. Just enter a number and see the result.

Educational

Learn how binary conversion works with detailed step-by-step explanations.

Accurate

Get precise results every time with built-in verification to check your answers.

Enter any positive integer

Conversion Results:

Decimal (Base 10)

42

Binary (Base 2)

101010

Octal (Base 8)

52

Hexadecimal (Base 16)

2A

Division Method Steps:

1. 42 ÷ 2 = 21 remainder 0

2. 21 ÷ 2 = 10 remainder 1

3. 10 ÷ 2 = 5 remainder 0

4. 5 ÷ 2 = 2 remainder 1

5. 2 ÷ 2 = 1 remainder 0

6. 1 ÷ 2 = 0 remainder 1

Binary result: 101010 (read remainders bottom to top)

Verification:

Position values:

Position 5: 1 × 2^5 = 32

Position 4: 0 × 2^4 = 0

Position 3: 1 × 2^3 = 8

Position 2: 0 × 2^2 = 0

Position 1: 1 × 2^1 = 2

Position 0: 0 × 2^0 = 0

Sum: 0×2^0(1) + 1×2^1(2) + 0×2^2(4) + 1×2^3(8) + 0×2^4(16) + 1×2^5(32) = 42

How Decimal to Binary Conversion Works

1

Input Number

Enter decimal value

2

Divide by 2

Record remainders

3

Repeat

Until quotient is 0

42₁₀ = 101010₂
Base conversion

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Conversion Formulas and Methods

Division Method Formula

Decimal ÷ 2 = Quotient + Remainder

Repeat until quotient = 0

Example: 42 ÷ 2 = 21 remainder 0

21 ÷ 2 = 10 remainder 1

10 ÷ 2 = 5 remainder 0

5 ÷ 2 = 2 remainder 1

2 ÷ 2 = 1 remainder 0

1 ÷ 2 = 0 remainder 1

Result: 101010₂

Position Value Formula

Decimal = Σ(bit × 2^position)

Sum of powers of 2

Example: 101010₂

= 1×2⁵ + 0×2⁴ + 1×2³ + 0×2² + 1×2¹ + 0×2⁰

= 1×32 + 0×16 + 1×8 + 0×4 + 1×2 + 0×1

= 32 + 0 + 8 + 0 + 2 + 0

= 42₁₀

Base Conversion Rules

Base₁₀ → Base₂

Successive division by 2

Binary: Uses digits 0, 1

Octal: Uses digits 0-7

Hexadecimal: Uses 0-9, A-F

Powers of 2: 1, 2, 4, 8, 16, 32, 64...

Each position = base^power

Decimal to Binary Conversion Table

DecimalBinaryOctalHexadecimalBit Length
11111 bits
210222 bits
4100443 bits
810001084 bits
161000020105 bits
3210000040206 bits
641000000100407 bits
12810000000200808 bits
2561000000004001009 bits
5121000000000100020010 bits
1,02410000000000200040011 bits
2,048100000000000400080012 bits
4,096100000000000010000100013 bits
8,1921000000000000020000200014 bits
16,38410000000000000040000400015 bits

Note: This table shows powers of 2 and their binary representations. Each row represents 2^n where n increases by 1.

Binary Number System Progression Chart

110100100010000100000Powers of 2Binary Length

2⁰

1
1
1 bit

2
10
2 bits

4
100
3 bits

8
1000
4 bits

2⁴

16
10000
5 bits

2⁵

32
100000
6 bits

Practice Problems with Step-by-Step Solutions

Problem 1: Convert 75 to binary

75 ÷ 2 = 37 remainder 1

37 ÷ 2 = 18 remainder 1

18 ÷ 2 = 9 remainder 0

9 ÷ 2 = 4 remainder 1

4 ÷ 2 = 2 remainder 0

2 ÷ 2 = 1 remainder 0

1 ÷ 2 = 0 remainder 1

Solution: 75₁₀ = 1001011₂

Problem 2: Convert 156 to binary

156 ÷ 2 = 78 remainder 0

78 ÷ 2 = 39 remainder 0

39 ÷ 2 = 19 remainder 1

19 ÷ 2 = 9 remainder 1

9 ÷ 2 = 4 remainder 1

4 ÷ 2 = 2 remainder 0

2 ÷ 2 = 1 remainder 0

1 ÷ 2 = 0 remainder 1

Solution: 156₁₀ = 10011100₂

Problem 3: Convert 11010₂ to decimal

Position values: 1×2⁴ + 1×2³ + 0×2² + 1×2¹ + 0×2⁰

= 1×16 + 1×8 + 0×4 + 1×2 + 0×1

= 16 + 8 + 0 + 2 + 0

Solution: 11010₂ = 26₁₀

Problem 4: Convert 200 to hexadecimal

200 ÷ 16 = 12 remainder 8

12 ÷ 16 = 0 remainder 12 (C in hex)

Read remainders bottom to top: C8

Solution: 200₁₀ = C8₁₆

Problem 5: Convert 127 to octal

127 ÷ 8 = 15 remainder 7

15 ÷ 8 = 1 remainder 7

1 ÷ 8 = 0 remainder 1

Read remainders bottom to top: 177

Solution: 127₁₀ = 177₈

Problem 6: Convert 1111₂ to all bases

Binary to Decimal: 1×8 + 1×4 + 1×2 + 1×1 = 15

Decimal to Octal: 15 ÷ 8 = 1 remainder 7 → 17₈

Decimal to Hex: 15 = F₁₆

Solution: 1111₂ = 15₁₀ = 17₈ = F₁₆

5 Daily Uses of Binary Conversion

1

Programming code uses binary for computer instructions

2

Digital cameras store photos in binary format

3

Internet routers use binary for network addresses

4

Mobile apps convert data to binary for storage

5

Gaming consoles process graphics using binary numbers

What is Decimal to Binary Conversion?

Understanding Decimal Numbers

Decimal numbers are the numbers we use every day. They use ten digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. This is called base-10 because it has ten different symbols. When we count, we go from 0 to 9, then start over with 10.

Each position in a decimal number represents a power of 10. For example, in the number 123, the 3 is in the ones place (10⁰), the 2 is in the tens place (10¹), and the 1 is in the hundreds place (10²).

Understanding Binary Numbers

Binary numbers use only two digits: 0 and 1. This is called base-2 because it has only two symbols. Binary is the language that computers speak. Every piece of information in a computer is stored as binary numbers.

Each position in a binary number represents a power of 2. For example, in the binary number 101, reading from right to left: the first 1 is 2⁰ (which equals 1), the 0 is 2¹ (which equals 0), and the last 1 is 2² (which equals 4). So 101 in binary equals 1+0+4 = 5 in decimal.

Why Do We Need Binary Conversion?

Converting decimal to binary is important because computers only understand binary. When you type a number on your keyboard, the computer converts it to binary to process it. When programmers write code, they often need to work with binary numbers directly.

Binary conversion helps in computer programming, digital electronics, network settings, and understanding how computers store data. It's also useful for students learning computer science and anyone working with technology.

How Decimal to Binary Conversion Works

The Simple Division Method

The easiest way to convert decimal to binary is using the division method. Here's how it works in simple steps:

Step-by-Step Process:

  1. Take your decimal number and divide it by 2
  2. Write down the remainder (it will be either 0 or 1)
  3. Take the result (quotient) and divide it by 2 again
  4. Keep writing down the remainders
  5. Continue until the quotient becomes 0
  6. Read all the remainders from bottom to top - that's your binary number!

Example: Convert 13 to Binary

13 ÷ 2 = 6 remainder 1

6 ÷ 2 = 3 remainder 0

3 ÷ 2 = 1 remainder 1

1 ÷ 2 = 0 remainder 1

Reading remainders from bottom to top: 1101

So 13 in decimal = 1101 in binary

Alternative Method: Powers of 2

Another way to convert is using powers of 2. This method helps you understand what each binary digit means.

Powers of 2 Table:

2⁰ = 1

2¹ = 2

2² = 4

2³ = 8

2⁴ = 16

2⁵ = 32

2⁶ = 64

2⁷ = 128

Example: Convert 13 using Powers of 2

13 is less than 16 (2⁴) but greater than 8 (2³)

So we use: 8 + 4 + 1 = 13

In powers of 2: 2³ + 2² + 2⁰

Binary positions: 1101

Result: 13₁₀ = 1101₂

Common Decimal to Binary Examples

Everyday Numbers in Binary

Here are some common decimal numbers and their binary equivalents. These examples show how different types of numbers look in binary format. Notice the patterns!

11

The smallest positive number - just one bit needed

1 = 2⁰ = 1

5101

Five uses three bits with a pattern

5 = 4 + 1 = 2² + 2⁰

101010

Ten shows alternating pattern in binary

10 = 8 + 2 = 2³ + 2¹

1610000

Perfect power of 2 - only one bit is 1

16 = 2⁴

2511001

Twenty-five combines multiple powers of 2

25 = 16 + 8 + 1 = 2⁴ + 2³ + 2⁰

50110010

Fifty is an even number ending in 0

50 = 32 + 16 + 2 = 2⁵ + 2⁴ + 2¹

1001100100

One hundred needs seven bits to represent

100 = 64 + 32 + 4 = 2⁶ + 2⁵ + 2²

12810000000

Another perfect power of 2 with 8 bits

128 = 2⁷

25511111111

Maximum 8-bit number - all bits are 1

255 = 128+64+32+16+8+4+2+1

Easy Patterns to Remember

  • Powers of 2: Numbers like 1, 2, 4, 8, 16, 32 have only one '1' bit in binary
  • Even numbers: Always end with '0' in binary (like 10, 50, 100)
  • Odd numbers: Always end with '1' in binary (like 1, 5, 25)
  • All 1's: Numbers like 7 (111), 15 (1111), 31 (11111) are 2ⁿ - 1
  • Zero: The only number that is just '0' in binary

Quick Recognition Tips

  • Count the bits: More bits mean bigger numbers
  • First bit: If it starts with 1, the number is at least that power of 2
  • Last bit: Tells you if the number is odd (1) or even (0)
  • All zeros: Only the number 0 has all zeros
  • Mixed pattern: Most numbers have a mix of 1s and 0s

Real-World Examples

Age 25: 11001 in binary (5 bits needed)

Days in year (365): 101101101 in binary (9 bits)

Hours in day (24): 11000 in binary (5 bits)

Minutes in hour (60): 111100 in binary (6 bits)

Seconds in minute (60): 111100 in binary (6 bits)

Months in year (12): 1100 in binary (4 bits)

Frequently Asked Questions About Decimal to Binary Conversion

What is the difference between decimal and binary numbers?

Decimal numbers use 10 digits (0, 1, 2, 3, 4, 5, 6, 7, 8, 9) and are based on powers of 10. This is the number system we use in daily life for counting money, telling time, and measuring things.

Binary numbers use only 2 digits (0 and 1) and are based on powers of 2. Computers use binary because electronic switches can only be in two states: on (1) or off (0). This makes binary perfect for digital devices like computers, phones, and calculators.

How do I convert large decimal numbers to binary?

For large numbers, use the same division method but it will take more steps. Keep dividing by 2 and write down each remainder until you reach 0. Our online calculator can handle numbers up to 65,535 instantly.

For numbers bigger than 65,535, you can use programming languages like Python, JavaScript, or online calculators that support larger numbers. The method stays the same - just more divisions!

Why do computers use binary instead of decimal?

Computers are made of millions of tiny electronic switches called transistors. Each switch can only be in two states: on or off. It's much easier and more reliable to represent these two states as 1 (on) and 0 (off) than to try to create 10 different states for decimal digits.

Think of it like a light switch - it's either on or off. It would be very complicated and unreliable to make a switch that could be in 10 different positions accurately.

What is the maximum number I can convert with this tool?

Our converter works with numbers from 0 to 65,535. This range covers most everyday needs and educational purposes. The number 65,535 is special because it's the largest number you can represent with 16 binary digits (bits).

If you need to convert larger numbers, you can use the same division method by hand or use programming tools. The process is exactly the same, just with more steps.

How can I check if my binary conversion is correct?

The best way to verify is to convert the binary number back to decimal. Take each binary digit, multiply it by its corresponding power of 2, and add them all up.

For example, to check if 1010 in binary equals 10 in decimal: (1×8) + (0×4) + (1×2) + (0×1) = 8 + 0 + 2 + 0 = 10. Our calculator shows this verification step automatically.

Can I convert negative numbers to binary?

Yes, but negative numbers in binary are more complex. Computers use a special method called "two's complement" to represent negative numbers. This involves flipping all the bits and adding 1.

Our basic converter focuses on positive integers, which are easier to understand and more commonly used in learning. For negative numbers, you'll need specialized tools or programming knowledge.

Where is binary conversion used in real life?

Binary conversion is everywhere in technology! Programmers use it when writing software, network engineers use it for IP addresses, and digital artists use it for color codes. Even your smartphone uses binary to store your photos, messages, and apps.

Students learning computer science, electronics technicians, and anyone working with digital systems need to understand binary conversion. It's also useful for understanding how file sizes work (like KB, MB, GB).

How many bits do I need for a specific decimal number?

The number of bits needed depends on how big your decimal number is. Here's a simple guide: Numbers 0-1 need 1 bit, 0-3 need 2 bits, 0-7 need 3 bits, 0-15 need 4 bits, and so on.

A quick rule: if your number is less than 2^n, then you need n bits. For example, numbers less than 256 (which is 2^8) need 8 bits. Our calculator shows you exactly how many bits your number needs.

Is there a pattern to binary numbers?

Yes! Binary numbers follow clear patterns. Even numbers always end in 0, odd numbers always end in 1. Powers of 2 (like 1, 2, 4, 8, 16) have only one '1' bit. Numbers that are one less than a power of 2 (like 3, 7, 15, 31) have all '1' bits.

Learning these patterns makes binary conversion much easier and helps you spot mistakes quickly.

What's the easiest way to learn binary conversion?

Start with small numbers like 1-15 and practice the division method. Use our calculator to check your work. Try to memorize common numbers like powers of 2 (1, 2, 4, 8, 16, 32, 64, 128).

Practice converting your age, the current year, or other meaningful numbers. The more you practice, the easier it becomes. Don't worry about making mistakes - that's how you learn!

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Quick Reference

📏1 meter
3.28 feet
⚖️1 kilogram
2.2 pounds
🌡️0°C
32°F
🥤1 liter
0.26 gallon