Please Note: This article is written for users of the following Microsoft Excel versions: 2007, 2010, 2013, 2016, 2019, 2021, and Excel in Microsoft 365. If you are using an earlier version (Excel 2003 or earlier), this tip may not work for you. For a version of this tip written specifically for earlier versions of Excel, click here: Converting to Octal.
Written by Allen Wyatt (last updated October 26, 2024)
This tip applies to Excel 2007, 2010, 2013, 2016, 2019, 2021, and Excel in Microsoft 365
There are four types of numbering systems commonly used in programming: binary, octal, decimal, and hexadecimal. Each is simply a different method of expressing the exact same values. Excel makes it easy to convert between decimal and octal numbers and provides two worksheet functions for that very purpose.
The first function is the DEC2OCT function. Suppose you have a decimal value in cell B7, and you want to know how to express that value in octal. In a different cell you could use the following formula:
=DEC2OCT(B7)
If the value in B7 was 456, the result of the above formula would be 710. An interesting fact (and potential "gottcha") is that when the conversion is completed, Excel considers the result to be a number. Thus, if you added 8 to the resulting value above (710), Excel would return 718—a value impossible in octal. This simply means that Excel doesn't keep track of the numbering system used in a particular cell; it expects you to do that.
If you want to convert numbers back the other way, from octal to decimal, you can use the OCT2DEC worksheet function:
=OCT2DEC(B8)
If you try to use this function with a value that is clearly not octal (such as 718), then Excel returns a #NUM! error value.
ExcelTips is your source for cost-effective Microsoft Excel training. This tip (5656) applies to Microsoft Excel 2007, 2010, 2013, 2016, 2019, 2021, and Excel in Microsoft 365. You can find a version of this tip for the older menu interface of Excel here: Converting to Octal.
Dive Deep into Macros! Make Excel do things you thought were impossible, discover techniques you won't find anywhere else, and create powerful automated reports. Bill Jelen and Tracy Syrstad help you instantly visualize information to make it actionable. You’ll find step-by-step instructions, real-world case studies, and 50 workbooks packed with examples and solutions. Check out Microsoft Excel 2019 VBA and Macros today!
The MODE function is used to determine the most frequently recurring value in a range. This tip explains how to use the ...
Discover MoreVLOOKUP is a great function to use in accessing data based on a lookup value. Problem is, you can't easily return ...
Discover MoreThe UNIQUE function can be used to evaluate a range and return the unique values in that range. Understanding how the ...
Discover MoreFREE SERVICE: Get tips like this every week in ExcelTips, a free productivity newsletter. Enter your address and click "Subscribe."
2024-10-26 10:23:35
JMJ
A famous octal joke: Why is oct 31st the Xmas of geeks? Because 31OCT=25DEC!
Got a version of Excel that uses the ribbon interface (Excel 2007 or later)? This site is for you! If you use an earlier version of Excel, visit our ExcelTips site focusing on the menu interface.
FREE SERVICE: Get tips like this every week in ExcelTips, a free productivity newsletter. Enter your address and click "Subscribe."
Copyright © 2025 Sharon Parq Associates, Inc.
Please Note:
This article is written for users of the following Microsoft Excel versions: 2007, 2010, 2013, 2016, 2019, 2021, and Excel in Microsoft 365. If you are using an earlier version (Excel 2003 or earlier), this tip may not work for you. For a version of this tip written specifically for earlier versions of Excel, click here:
Comments