Octal to Hexadecimal Converter
Convert octal numbers to hexadecimal (base 16) instantly via a binary intermediate. Octal expands to 3-bit groups, which regroup into 4-bit hex digits.
Common Octal to Hex Values
How to Convert Octal to Hex
Octal digits are 3 bits and hex digits are 4 bits, so there is no direct digit mapping. Route the conversion through binary:
- Expand each octal digit to its 3-bit binary value
- Join the bits into one continuous binary string
- Regroup the bits into sets of four from the right, padding the left with zeros
- Convert each 4-bit group to a hex digit (0000=0 to 1111=F)
Example: Convert 377 (octal) to hex:
- 3 → 011, 7 → 111, 7 → 111, giving 011111111
- Regroup into 4s from the right: 1111 1111
- 1111 = F, 1111 = F → FF (hex)
Code Examples
const octal = "377";
parseInt(octal, 8).toString(16); // "ff"Frequently Asked Questions
How do I convert octal to hex?
Convert through binary: expand each octal digit to 3 bits, then regroup all the bits into sets of 4 from the right and map each group to a hex digit (0000=0 up to 1111=F).
Why can't I map octal digits straight to hex?
Octal uses 3 bits per digit and hex uses 4 bits per digit, so the digit boundaries do not line up. Regrouping the underlying bits in binary is the reliable method.
Can I use a 0o prefix?
Yes. Both plain octal like 377 and prefixed octal like 0o377 work. Only the digits 0 through 7 are valid octal input.
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