Hexadecimal to Octal Converter

Type a Hexadecimal number and get Octal instantly — plus every other base at the same time.

From To Mode

Number

Every base updates as you type; click bits to toggle them. Digit separators (_, spaces) are allowed. In two's complement mode the binary/octal/hex rows show the bit pattern and the decimal row shows the signed value. Choose Text to convert ASCII/UTF-8 text to bytes in any base — or bytes back to text.

How to convert Hexadecimal to Octal

Octal and hexadecimal digits don't line up with each other (3 bits vs 4 bits), so the fastest route is through binary: expand each hexadecimal digit to bits, then regroup the bits in 3s from the right and read off the octal digits. No decimal arithmetic needed.

Worked example

Convert 2F3 (hexadecimal) to octal:

Expand 2F3 to binary: 1011110011
Regroup the bits in 3s from the right: 001 011 110 011
Read off the digits: 1363

So 2F3 in hexadecimal is 1363 in octal.

Hexadecimal to Octal conversion table

Hexadecimal	Octal
0	0
1	1
2	2
3	3
4	4
5	5
6	6
7	7
8	10
9	11
A	12
B	13
C	14
D	15
E	16
F	17

Frequently asked questions

Can this handle numbers larger than 64 bits?: Yes. Conversion runs on arbitrary-precision integers, so numbers of any length convert exactly. Many online converters silently lose precision above 2⁵³ (about 16 decimal digits) — this one doesn't.
How do I convert negative numbers?: A leading minus sign works in every base. For the bit-pattern view programmers usually want, switch the mode to two's complement at 8, 16, 32, or 64 bits — then binary, octal, and hex show the bit pattern while decimal shows the signed value.
Can I convert the other way, or to other bases?: Use the Octal to Hexadecimal converter, or just change the From/To dropdowns above — every common base is shown at once anyway, and a Text mode converts ASCII to bytes and back.

Need arithmetic rather than conversion — adding hex numbers, shifting bits, masking? Use the programmer's calculator.