Microsoft Fixes Excel Calculation Bug

Microsoft confirms it has fixed an Excel calculation results bug, but declines to fully explain the cause.

Microsoft says it has fixed an Excel bug, which caused the spreadsheet to display erroneous calculation results, even though it performed the calculation correctly and stored it in Excels memory.

In an Oct. 9 posting on the Excel section of MSDN [Microsoft Developer Network,] the Excel Team served notice that, "as of today, fixes for this issue in Excel 2007 and Excel Services 2007 are available for download. Microsoft acknowledged the problem about two weeks ago on MSDN involving the calculation of numbers in its ever-popular Excel software program.

The issue, according to the Excel staff, was introduced when Microsofts development team made changes to the Excel calculation logic in Office 2007.

The errors are not in the calculations themselves; the result of the calculations stored in Excels memory are correct. But the result that appeared in the Excel spreadsheet is incorrect.


Click here to read more about the Excel calculation issue.

"Said another way, =850*77.1 will display an incorrect value, but if you then multiply the result by 2, you will get the correct answer," Microsoft team blogger David Gainer wrote in a September posting.

According to the post, the Excel Team is in the process of adding the fix to Microsoft Update, "so that it will get automatically pushed to users running Excel 2007 or Excel Services 2008," wrote Gainer. The fix will also be included in the first service pack of Office 2007 when its released. That release date has not yet been finalized.

In responding to a user question regarding the Excel snafu, Gainer said his team is not planning to share details of what actually went wrong with the Excel calculations beyond what it has already communicated: "that the issue occurred in formatting of floating point numbers near 65,565 and 65,536. It was code that we introduced as part of the calculation overhaul that we did for Excel 2007 however."


Check out eWEEK.coms for the latest news, reviews and analysis about productivity and business solutions.