Octal to Binary Converter
Convert octal numbers to binary, including fractions and negative numbers, with the working shown.
Change the values and press Calculate to work out your own figures.
Enter a octal number to write it in binary.
Show the working
- Write each octal digit as 3 bits: 111 101 101
- Join them and drop leading zeros: 111101101
How to use it
Enter a octal number to write it in binary.
Letters stand for digits above 9 (A = 10 … Z = 35) and can be typed in either case; prefixes such as 0b and 0x, spaces and underscores are ignored. Show the working gives each step.
Key facts
octal → binary: regroup the bits (3 per octal digit, 4 per hex digit)
How the conversion works
Because 8 = 2³ and 16 = 2⁴, each octal digit is exactly 3 bits and each hex digit exactly 4, so the conversion is done by grouping bits.
Questions
What is 755 in binary?
111101101.
Can I convert fractions?
Yes. Digits after the point are converted exactly; if they repeat forever in the new base, the repeating block is shown in parentheses.
Formulas
octal → binary: regroup the bits (3 per octal digit, 4 per hex digit)
Sources
Limitations
- Numbers have at most 1,000 characters; Roman numerals cover whole numbers from 1 to 3,999,999.