ModelSheet Software is one of our templates partners who provides great Excel spreadsheet templates. Today, please welcome our guest blogger, Dick Petti, from ModelSheet Software:

People tend to write off spreadsheets for moderately large analyses. This week I built a 216 MB financial plan template and delivered it to a user. This is the largest Excel workbook I have ever used. (This is the size of the xls file; the xlsx file is smaller.)

I tried out the template in Excel 2007 on a vintage 2008 Pentium PC with 2.0 GHz CPU and 4 GB RAM. I concluded that the 216 MB template is useful but less convenient than a 97 MB version of the same model, if interactive performance counts.
•    Entering a new value in a cell took 3-4 seconds, whereas the smaller version takes about one second.
•    Opening nine collapsed Excel groups on sheet 'Inputs' takes about 20 seconds, compared to 4-5 seconds for the smaller file.
Excel can handle even larger workbooks, but its interactive performance degrades.

We generated this workbook on a Pentium PC with a 64-bit version of MS-Windows and 8 GB of RAM, in roughly two hours. We estimate that this PC could handle an Excel workbook that is 10-20% larger, or about 250 MB, before running out of space. The size of Excel workbook that we can generate appears to be limited only by the amount of RAM and the amount of time available to the process.

10287580 You can see a small sample of the same financial plan template here: Business unit financial plan. The tools we use to build this spreadsheet are described at . Because of the way the model is generated, the huge template is no less reliable than the tiny sample.

Microsoft Excel has made great strides in handling larger workbooks, and our tools enable us to exploit that capability most effectively. I shudder to think what kind of effort would be required to manually build a 200 MB workbook with the complexity of our financial plan templates.

If you want to build spreadsheets of this complexity and this size (half this size is more useful when interactive performance counts), then drop me a line.

--Dick Petti  |

Thank you, Dick! Be sure to check out ModelSheet Software's templates on Office Online.