Summary

HEX2OCT converts hexadecimal text into octal text. If a value starts in base 16 and needs to end up in base 8, this function does that translation for you.

That is not as common as decimal conversion, but it is still useful when you move data between systems that use different number formats. In those cases, HEX2OCT saves you from converting through intermediate steps by hand.

Syntax

=HEX2OCT(number, [places])

number is the hex value to convert. places is optional and pads positive results with leading zeros.

The result stays in text form because the goal here is format conversion, not arithmetic. Use places when the octal output should match a set width. If you leave it out, Excel returns the shortest positive octal result it can.

Arguments

• number - [required] The hexadecimal value to convert. Excel accepts up to 10 characters.
• [places] - [optional] The minimum number of octal characters to return for positive values.

number must be a valid hexadecimal input. places is optional and mainly useful for fixed-width output. It affects positive results only. If the converted octal value is longer than the places value, Excel returns #NUM!.

HEX2OCT vs similar functions

HEX2OCT is the right choice when the destination format needs to stay in octal text:

Using HEX2OCT

The main use is direct translation between two technical number systems. If one system gives you hex and another expects octal, HEX2OCT helps you move between them without first converting the value manually.

The places argument can pad positive results with leading zeros. That matters when the output needs to match a fixed display width or a code format. If the converted result is longer than the places value, Excel returns #NUM!.

Signed negative values work differently. Excel ignores places for negative input and returns a full signed octal result, which is why HEX2OCT("FFFFFFFFFF") gives a 10-character octal string instead of a short one.

Example 1 - Convert 3A to octal

This is the direct hex-to-octal conversion pattern. Excel takes the compact hex value 3A and returns the octal equivalent 72. That is helpful when data has to move into a base-8 format without first being rewritten manually in decimal.

=HEX2OCT("3A") // Returns "72"

Example 2 - Pad the result to 3 characters

Padding matters when the output is expected to match a fixed-width octal code such as a permission-style value. Here, 1ED becomes 755, and the width keeps the result in the conventional form normally used for that kind of code.

=HEX2OCT("1ED", 3) // Returns "755"

Example 3 - Convert a negative hex value

This example shows the signed engineering-format behavior during conversion. The hex input represents -1, so HEX2OCT returns the full signed octal form 7777777777 rather than a short unsigned result.

=HEX2OCT("FFFFFFFFFF") // Returns "7777777777"

Example 4 - Pad FF as a 4-character octal value

The value FF becomes 0377, which is the same octal value but in a fixed-width form. That is useful when the worksheet needs column-aligned codes or outputs that must follow an exact field layout.

=HEX2OCT("FF", 4) // Returns "0377"

Quick recap

• Converts hex to octal: HEX2OCT returns base-8 text from a base-16 value.
• Places pads positive values: Use it for fixed-width octal output.
• Negative values ignore places: Excel returns a full signed octal result.
• Returns text: This is a formatting and translation function, not a numeric math function.
• Useful for cross-format work: It helps when two systems use different technical bases.