What is a hexadecimal number?

Hexadecimal (base-16) uses sixteen symbols: 0-9 for values zero through nine, and A-F (or a-f) for values ten through fifteen. It is widely used in computing to represent binary data compactly.

What is an octal number?

Octal (base-8) uses eight symbols: 0 through 7. Each octal digit represents exactly three binary bits. It was historically common in computing and is still used for Unix file permissions.

How is hex converted to octal?

The standard approach is a two-step process: first convert the hexadecimal number to its decimal (base-10) equivalent, then convert that decimal value to octal. This tool performs both steps and shows you the intermediate decimal value.

Does the tool accept the 0x prefix?

Yes. You can enter values with or without the 0x or 0X prefix — both are accepted and stripped automatically before conversion.

Is there a size limit on the hex input?

The tool uses JavaScript BigInt internally, so it can handle arbitrarily large hexadecimal values without losing precision.

What happens if I enter an invalid character?

Invalid characters (anything outside 0-9 and A-F) trigger an inline error message. The input is highlighted and no result is shown until the value is corrected.

Hexadecimal to Octal Converter

Name: Hexadecimal to Octal Converter
Availability: InStock
Author: Nham Vu

Enter a hexadecimal value and instantly get its octal equivalent — no server needed.

Hexadecimal Input

Enter hex value (0-9, A-F, optional 0x prefix)

Quick Examples

Octal Result

Enter a hex value and click Convert

Summary

Enter a hexadecimal value and instantly get its octal equivalent — no server needed.

How it works

Enter a hexadecimal number in the input field (e.g. 1A3F or 0x1A3F).
The tool parses the hex digits (0-9, A-F) and validates the input.
Internally, the hex value is converted to its decimal (base-10) integer.
The decimal integer is then converted to octal (base-8) notation.
The octal result is displayed along with the intermediate decimal value.
Click Copy to copy the octal result to your clipboard.

Use cases

Translating memory addresses from hex debug output to octal for legacy systems.
Learning number base conversions for computer science courses.
Verifying manual hex-to-octal calculations.
Converting Unix file permission codes expressed in hex to their octal form.
Working with embedded systems that use octal register notation.
Quick base conversion during CTF (Capture the Flag) security challenges.
Cross-checking output from programming language base-conversion functions.
Teaching or studying positional numeral systems.

Frequently Asked Questions

Last updated: 2026-06-13 · Reviewed by Nham Vu