💻Binary Converter
Convert numbers between binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16) instantly with bit count and byte analysis.
Prefer to skip the form? Scroll down and Ask AI Instead. Just describe your situation and let AI handle the math for you in seconds.
Converted Value
11111111
Decimal 255 = Binary 11111111. Decimal value: 255. 8 bits, 1 byte(s).
Number Base Representations
11111111
377
255
FF
Advertisement
728 × 90
✦ Ask AI Instead
Binary Converter: Convert Decimal to Binary, Hex, and Octal Online
This binary converter and decimal to binary converter lets you instantly translate numbers between the four most common numeral systems used in computing and mathematics: binary (base-2), octal (base-8), decimal (base-10), and hexadecimal (base-16). Whether you are a student learning the binary number system or a developer reading memory addresses, this tool handles the conversion in one step and shows all representations at once.
The Four Number Bases Explained
Every numeral system works by assigning place values that are powers of the base. A digit's contribution to the total is its face value multiplied by the base raised to its position. The systems differ only in how many digit symbols they use and what place values they generate.
Binary to Decimal Converter: Understanding Base-2
Binary uses only the digits 0 and 1. Each position represents a successive power of two, starting at 2^0 = 1 on the right. Because electronic circuits can reliably distinguish two voltage states (on and off), binary is the native language of every processor, memory chip, and digital logic gate. A single binary digit is called a bit; eight bits form a byte, which can hold values from 0 (00000000) to 255 (11111111).
To convert binary to decimal, multiply each bit by its place value and sum the results. The binary number 1011 equals (1 x 8) + (0 x 4) + (1 x 2) + (1 x 1) = 11 in decimal.
Convert Decimal to Binary Online Step by Step
The standard method for converting a decimal number to binary uses repeated division. Divide the number by 2, record the remainder (0 or 1), then repeat with the quotient until the quotient reaches zero. Reading the remainders from last to first gives the binary representation.
- Convert 43 to binary: 43 / 2 = 21 remainder 1
- 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
- Reading remainders upward: 43 in decimal = 101011 in binary.
Verify: 32 + 0 + 8 + 0 + 2 + 1 = 43. This calculator performs every step automatically and groups bits into nibbles (sets of 4) for easier reading.
Binary Hexadecimal and Octal Number Converter
Hexadecimal (base-16) extends the digit set to 0 through 9 and A through F, where A = 10, B = 11, C = 12, D = 13, E = 14, and F = 15. Because 16 = 2^4, each hex digit maps exactly to four binary bits (a nibble). This makes hex an extremely compact notation for binary data: the byte 11111111 in binary is simply FF in hex. Memory addresses, SHA-256 hash values, MAC addresses, and web color codes (#FF6600) all use hexadecimal for this reason.
Octal (base-8) maps each digit to exactly three binary bits. While octal is less common today, it still appears in Unix and Linux file permission notation, where the mode 755 represents the binary pattern 111 101 101 encoding read, write, and execute permissions for owner, group, and others.
Bits, Bytes, and Powers of Two
Understanding binary math requires familiarity with powers of two, since every binary place value is one of them:
- 1 bit holds 2^1 = 2 possible values (0 or 1).
- 1 byte (8 bits) holds 2^8 = 256 values (0 to 255).
- 1 kilobyte (KB) = 2^10 = 1,024 bytes.
- 1 megabyte (MB) = 2^20 = 1,048,576 bytes.
- 1 gigabyte (GB) = 2^30 = 1,073,741,824 bytes.
Storage and memory capacities follow these binary multiples, which is why a "1 GB" file drive holds slightly more than one billion bytes when measured in powers of two.
Why Computers Use Binary Math
Digital circuits are built from transistors that operate in two states: conducting (1) or not conducting (0). Designing circuits that reliably distinguish ten discrete voltage levels for a decimal system would demand far greater precision and yield far more errors under real-world conditions like temperature variation and electrical noise. Two-state logic is robust, manufacturable at nanometer scale, and maps cleanly onto Boolean algebra, which underpins all logical operations in software and hardware design.
Hexadecimal in Web Design and Development
Web colors use three hexadecimal pairs, one each for red, green, and blue intensity. Each pair ranges from 00 (0 in decimal) to FF (255 in decimal), producing 256 x 256 x 256 = 16,777,216 possible colors. Pure white is #FFFFFF, pure black is #000000, and a vivid orange such as #FF6600 means red at full intensity (255), green at 102, and blue at 0. Understanding this binary representation of color values is fundamental to CSS, image processing, and digital graphics.
Frequently Asked Questions
How do I convert a decimal number to binary?
Divide the decimal number by 2 repeatedly, recording the remainder (0 or 1) at each step, until the quotient reaches zero. Then read the remainders from bottom to top. For example, to convert 25: 25/2=12 R1, 12/2=6 R0, 6/2=3 R0, 3/2=1 R1, 1/2=0 R1. Reading upward gives 11001, so 25 in decimal equals 11001 in binary. This calculator automates that process and also shows octal and hex equivalents.
How do I convert binary to decimal?
Multiply each binary digit by 2 raised to its position (starting from 0 on the right) and add all the results. For 10110: (1 x 16) + (0 x 8) + (1 x 4) + (1 x 2) + (0 x 1) = 16 + 0 + 4 + 2 + 0 = 22. A quick shortcut: identify which powers of two correspond to the 1 bits and add them together.
What is the difference between binary and hexadecimal?
Binary (base-2) uses only 0 and 1, so large numbers require many digits. Hexadecimal (base-16) uses digits 0 through 9 and A through F, compressing four binary bits into a single hex digit. The number 255 takes eight digits in binary (11111111) but just two in hex (FF). Programmers prefer hex because it is readable and maps cleanly to bytes, while binary is the actual representation inside the hardware.
Why do computers use binary?
Computers use binary because electronic circuits naturally have two stable states: high voltage (1) and low voltage (0). Reliably distinguishing just two states is far simpler and more noise-resistant than distinguishing ten states for decimal. Binary also aligns perfectly with Boolean logic (true/false, on/off), which is the foundation of all logical and arithmetic operations performed by a processor.