What is a number base?

A number base (or radix) is the number of unique digits used to represent numbers. Binary (base 2) uses 0-1, octal (base 8) uses 0-7, decimal (base 10) uses 0-9, and hexadecimal (base 16) uses 0-9 and A-F. Different bases are useful in different contexts.

Why do programmers use different number bases?

Binary is the native language of computers. Hexadecimal is a compact way to represent binary (each hex digit = 4 binary digits). Octal was historically used in some systems. Decimal is natural for humans. Programmers often need to convert between these bases for debugging, bit manipulation, and understanding memory addresses.

What is hexadecimal used for?

Hexadecimal is widely used in programming for: color codes (e.g., #FF0000 for red), memory addresses, binary data representation, and machine code. Each hex digit represents 4 bits, making it a compact way to work with binary data. For example, byte values (0-255) fit in two hex digits (00-FF).

Can I convert negative numbers?

Yes, but only in decimal input mode. The converter will show the two's complement representation in other bases. For example, -1 in decimal becomes a very large positive number in binary because JavaScript uses two's complement for negative numbers.

What's the maximum number I can convert?

The converter supports numbers up to JavaScript's safe integer limit (2^53 - 1 = 9,007,199,254,740,991). This is approximately 9 quadrillion. Larger numbers may lose precision due to JavaScript's number representation.

How do I read the results?

Each result shows the number in a different base. Binary shows the number as a sequence of 0s and 1s. Octal uses digits 0-7. Decimal is the familiar base-10 number. Hexadecimal uses 0-9 and A-F (uppercase). All results represent the same value, just in different representations.

Tools

Select Base

Input Value (Decimal)

Result

BIN

11111111

OCT

377

DEC

255

HEX

Number Base Converter — Convert Between Binary, Octal, Decimal & Hex

Free number base converter to convert numbers between binary, octal, decimal, and hexadecimal. Instant conversion with step-by-step explanation. Perfect for programmers and students. All calculations run locally in your browser.

Features

✓Convert between binary, octal, decimal, and hexadecimal
✓Instant conversion as you type
✓Support for negative numbers in decimal
✓Validate input for each number base
✓Display all conversions simultaneously
✓Copy result with one click
✓Perfect for programming and learning
✓Useful for color code conversion
✓Support for large numbers (up to safe integer)
✓All calculations run locally in your browser

How to Use

1Select the input number base (binary, octal, decimal, or hexadecimal).
2Enter your number in the input field.
3All conversions display instantly.
4Click copy button to copy any result.
5Switch input base to convert from different formats.

Frequently Asked Questions

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