Skip to main content

Number Base Converter

Easily convert numbers between different bases like binary, decimal, and hexadecimal.

From

To

How to Use the Number Base Converter

The Number Base Converter is a versatile tool designed for developers, students, and mathematicians to convert numbers between different numeral systems. It supports the most common bases used in computing and mathematics, providing a quick and reliable way to handle number conversions.

To use the converter, enter a number in the "From" section and select its current base. The tool will instantly display the converted number in the "To" section, where you can select the desired target base. This streamlined process eliminates manual calculations and reduces the risk of errors.

  • Decimal (Base 10): The standard system for denoting integer and non-integer numbers.
  • Binary (Base 2): The numeral system used by digital electronics and computers.
  • Hexadecimal (Base 16): Commonly used in computing as a more human-friendly representation of binary-coded values.
  • Octal (Base 8): Another base sometimes used in computing, particularly in early systems.

Complete Guide to Number Systems

Understanding different number bases is fundamental to computer science and digital electronics. This guide explores binary, octal, decimal, and hexadecimal systems, their applications, and conversion techniques.

The Decimal System: Our Everyday Base

The decimal system (base 10) uses ten digits (0-9) and is the system we use daily. Each position represents a power of 10: ones (10⁰), tens (10¹), hundreds (10²), etc. For example, 425 = 4×100 + 2×10 + 5×1. This system is natural for us because we have ten fingers.

The Binary System: The Language of Computers

The binary system (base 2) uses only two digits: 0 and 1. It's the foundation of all computing because electronic circuits have two states: on (1) and off (0). Each position represents a power of 2: 1, 2, 4, 8, 16, 32, 64, 128... In binary, 1010 = 8+0+2+0 = 10 in decimal.

Hexadecimal: Compact Notation for Binary

Hexadecimal (base 16) uses sixteen symbols: 0-9 and A-F (A=10, B=11, C=12, D=13, E=14, F=15). It's popular because each hex digit represents exactly 4 binary bits, making conversion simple. For example, FF = 1111 1111 in binary = 255 in decimal. Web colors (#FF5733), memory addresses, and machine code use hexadecimal.

Octal: The Historical System

The octal system (base 8) uses digits 0-7. Historically important because each octal digit represents exactly 3 bits. It was used on older computers and remains present in Unix/Linux permissions (chmod 755). While less common today, it still appears in some low-level programming contexts.

Conversion Methods: Decimal to Other Bases

To convert decimal to another base, repeatedly divide by the base and record remainders. Example: 156 to binary. 156÷2=78 r0, 78÷2=39 r0, 39÷2=19 r1, 19÷2=9 r1, 9÷2=4 r1, 4÷2=2 r0, 2÷2=1 r0, 1÷2=0 r1. Read remainders bottom-up: 10011100.

Binary to Hexadecimal Conversion

Binary-to-hexadecimal conversion is direct thanks to the relationship 16=2⁴. Group bits by 4 (from right to left) and convert each group. Example: 11010110 → 1101 0110 → D6. Conversely, replace each hex digit with 4 bits: A3 → 1010 0011. This method avoids intermediate decimal calculations.

Practical Applications in Development

Developers use these bases daily. CSS colors are in hexadecimal (#RRGGBB). Bit masks use binary to manipulate individual flags. IP addresses can be represented in binary for subnet calculations. Hexadecimal is used to examine raw data in debuggers and hex editors.

Representing Negative and Floating-Point Numbers

In binary, negative numbers often use two's complement: invert all bits and add 1. For example, -5 in 8 bits: 5=00000101, invert=11111010, +1=11111011. Floating-point numbers use the IEEE 754 standard with sign, exponent, and mantissa. These concepts are crucial for understanding the limits of computer calculations.

Frequently Asked Questions About Number Bases

Computers use binary because electronic circuits have only two stable states: on (high voltage/current = 1) and off (low/no voltage = 0). This simplicity enables maximum reliability, simpler circuit construction, and resistance to electrical noise. Any other base would require distinguishing more states, increasing complexity and errors.