Excel File Types: XLSM Vs XLSX. Everywhere you look these days, people are using Microsoft Excel.

This program has done wonders for business, schools, and anyone else needing a fast and easy way to keep track of data.

It’s hard to find a company these days who isn’t using Microsoft Excel.

As more and more of us are using Excel though, we run into a problem. What Excel file extension should we use to save our spreadsheets? There have been a ton of file types and changes since Excel started in 1985, so what should you use?

With so many options all with the same letter combinations, what do we use? Are some better than others?

This article will show you the difference between two of the most common Excel file types: XLSM vs XLSX. After you read this, you’ll be a pro about knowing which one to use and when.

Benefits of Excel

Before we get into the nitty-gritty of file types, let’s look at the main reasons people use Microsoft Excel. If you’re struggling with Excel files types, don’t worry, this program is worth keeping.

Excel actually started in 1985 and has revolutionized data organization.

This program allows people who often don’t know much about computers to build charts and organize their data. They can also colour code their information to highlight facts.

All a company’s data can be stored in one place and can be rearranged with the touch of a button. This allows businesses to identify trends in their information. With Microsoft Office 365 and Google Sheets, companies can now share their data with others no matter where they are.

Excel File Types, History of XLSM vs XLSX

Prior to 2007, Microsoft Excel used XLS file formats which stores binary data. In the 2007 version, Microsoft introduced XLSX and XLSM. These programs store data with an XML format (Extensible Markup Language) instead of binary.

This allows Excel spreadsheets to be more compatible with other programs than older versions were.

Microsoft Excel needed to introduce two new file extensions in their 2007 version, one that was compatible with VBA macros and one that wasn’t.

Before you start scratching your head, wondering what the heck VBA macros is, take a look at the next section.

VBA Macros

One of the biggest differences in XLSM vs XLSX is VBA macros compatibility. That sounds like a lot of jargon, so let’s explain the term before we compare the excel file types.

VBA macros is a programming language that can be used in Microsoft Excel. We’re all familiar with the tedious, repetitive tasks we do in spreadsheets. This is often a lot of copying and pasting, rearranging, and shifting things around.

By using VBA macros, you are creating or coding programs to automatically do these simple tasks for you. Sounds like a huge time saver, right? Especially when it comes to data entry!

The only downside to VBA macros is that if someone else creates it, it may contain malicious programs. This is why you have to be careful where you get your macros files.

Now let’s look at the differences between the Excel file extensions XLSM vs XLSX.


XLSX was introduced in Microsoft 2007 to replace XLS. It can also open XML files which makes it even more helpful.

When you use Microsoft Excel, you are prompted to save your document. The automatic default is an XLSX file type. This means if you don’t choose a file extension, your spreadsheet will be saved as an XLSX file.

Microsoft describes XLSX like this:

“The default XML-based file format for Excel 2007-2013. Cannot store Microsoft Visual Basic for Applications (VBA) macro code […].”

XLSX is nice because it uses an open file format and can be used with a lot of other applications.

People like XLSX because it’s safe. It can’t actually store malicious codes, which is a huge plus. It also allows the most rows and columns possible.

One downside of XLSX is that it can’t save VBA macros. While this is great for preventing viruses, sometimes you need to save VBA macros files you’ve received or created.

XLSX also takes up a lot of disc space, more than any other excel file type. Since XLSX was invented in 2007, it is incompatible with Microsoft Excel versions from before 2003.

Now that you know the pros and cons of XLSX, let’s take a look at XLSM.


The biggest downside of XLSX was that you couldn’t store VBA macros. Well, that’s the biggest positive of XLSM. Anytime you try to save a VBA macros file in Excel, you will be prompted to use XLSM because it’s compatible with VBA macros.

Again this does leave you open to viruses and malicious software, so be careful what you save in this format and who you get your files from.

XLSM doesn’t take up as much disc space as XLSX, but is still a large Excel file format.

Like XLSX, XLSM uses an open file format and can be used with many other applications. It also allows the full amount of columns and rows. XLSM is compatible with all the functions in Excel and can save them all.

XLSM was created in the Microsoft Excel 2007 version as well, so it is incompatible with files from Excel versions prior to 2003. This basically means you’ll have to convert all of your oldest Excel file extensions.

What to use?

To sum up this discussion it comes down to what you’re doing in Excel. If you want to use VBA macros programs to make your job simpler, you need to use XLSM.

Again, just be careful that you or someone you trust is creating the file. This will prevent you from accidentally receiving malicious software.

If you do not need to use VBA macros, just use the default XLSX Excel file extension. This protects you from accidentally saving viruses and still gives you the freedom to save all the functions you use in Microsoft Excel.

Moving Forward

Now that you know the ins and outs of XLSM vs XLSX, it’s time to learn more about time-saving programs in Excel. You can request a free consultation here or email [email protected] to see how your business can be more efficient when using spreadsheets.