Binary to Octal Converter
Convert binary numbers to octal and back. Group 3 binary digits to get each octal digit.
Reviewed October 7, 2026 Runs in your browser — inputs are never stored
Octal
52
Decimal: 42
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 to Octal Converter
The binary to octal converter changes binary numbers to octal and back by grouping bits in threes, because each octal digit represents exactly three binary digits. Octal is still used for Unix file permissions and some older computing systems.
How to use it
- 1Choose binary → octal or octal → binary.
- 2Enter the number.
- 3Read the result.
- 4Copy, share or print the result with the buttons below it.
Worked example
101010 → 101 010 → 52 in octal. Octal 755 is 111 101 101 in binary.
How it works
Method
Group binary digits in sets of 3 from right: 101 010 → 5 2 → 52 (octal).
Common use cases
- Reading Unix file permissions
- Computer science homework
- Low-level programming
Frequently asked questions
A:111 binary = 7 octal = 7 decimal.
A:Octal was historically used in early computing (PDP systems). It is still used in Unix file permissions (e.g. chmod 755).
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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