Hexadecimal to Octal Converter
Convert hexadecimal numbers to octal (base 8) instantly via a binary intermediate. Hex expands to 4-bit groups, which regroup into 3-bit octal digits.
Common Hex to Octal Values
How to Convert Hex to Octal
Hex digits are 4 bits and octal digits are 3 bits, so they do not line up directly. The reliable method routes through binary:
- Expand each hex digit to its 4-bit binary value
- Join the bits into one continuous binary string
- Regroup the bits into sets of three from the right, padding the left with zeros
- Convert each 3-bit group to an octal digit
Example: Convert 0xFF to octal:
- F → 1111, F → 1111, giving 11111111
- Regroup into 3s: 011 111 111
- 011 = 3, 111 = 7, 111 = 7 → 377 (octal)
Code Examples
const hex = "ff";
parseInt(hex, 16).toString(8); // "377"Frequently Asked Questions
How do I convert hex to octal?
There is no direct digit mapping between hex and octal, so convert through binary: expand each hex digit to 4 bits, then regroup those bits into sets of 3 from the right and map each group to an octal digit.
Why go through binary?
Hex is base 16 (4 bits per digit) and octal is base 8 (3 bits per digit). Because 4 and 3 do not align, binary is the common ground that lets you regroup the bits cleanly.
Does it support the 0x prefix?
Yes. Enter hex with or without 0x, such as 0xFF or FF. Digits 0-9 and A-F are valid in either upper or lower case.
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