Binary Converter
Convert between decimal, binary, octal, and hexadecimal number systems in one place — for programmers, students, and engineers.
Reviewed October 7, 2026 Runs in your browser — inputs are never stored
Input format
Decimal (Base 10)
42
Binary (Base 2)
101010
Octal (Base 8)
52
Hexadecimal (Base 16)
2A
This tool provides general unit conversions for everyday and educational use. For regulated, legal, or scientific applications, verify conversion factors against the applicable official standard.
About the Binary Converter
The binary converter translates a number between decimal (base 10), binary (base 2), octal (base 8) and hexadecimal (base 16). Each base uses positional notation with powers of its base. Binary is the language of computer hardware, hexadecimal is a compact way to write binary, and octal is still used for Unix file permissions.
How to use it
- 1Choose the base you are entering.
- 2Type the number.
- 3Read the value in all four bases.
- 4Copy, share or print the result with the buttons below it.
Worked example
decimal 42 is 101010 in binary, 52 in octal and 2A in hexadecimal.
How it works
Number base systems
Binary (base 2) uses 0–1; Octal (base 8) uses 0–7; Decimal (base 10) uses 0–9; Hexadecimal (base 16) uses 0–9 and A–F.
Common use cases
- Computer science and programming homework
- Reading memory addresses and bit masks
- Electronics and networking
Frequently asked questions
A:42 in decimal = 101010 in binary = 2A in hexadecimal = 52 in octal.
A:Binary maps directly to electronic on/off states (voltage high/low), making it the natural language for digital circuits.
Reviewed for accuracy · Last updated October 7, 2026
Conversion factors are based on internationally defined SI units and standard metric/imperial equivalence tables.
CalcWisee Editorial Team
Calculator development and formula review
CalcWisee is an independent site founded by Ayman. Every calculator is built from a published formula or official definition, tested against hand-worked examples before it goes live, and corrected promptly when a reader reports an issue to ayman@calcwisee.com.
Expertise: Financial mathematics, Health and fitness formulas, Applied mathematics, Unit conversion standards
References & sources
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