Office Versions

By default, Office 2010, 2013 and 2016 install the 32-bit version.
You must explicitly choose to install the 64-bit version during setup.
Starting with Office 2019 and Microsoft 365, the default is the 64-bit version.

64 Bit Version

Excel 2010 was the first version available in 64-bit.
If you are using 32-bit Windows, you can only install 32-bit Office.
If you are using 64-bit Windows, you can install either 32-bit Office or 64-bit Office.

Reasons to choose 64-bit

The 64-bit version may perform better if you are working with large data sets and complex calculation.
You have a much larger amount of RAM (virtual memory) that can be accessed which is useful when using Power Pivot.
You can have files larger than 2GB.

Reasons to choose 32-bit

You want to use 32-bit add-ins
You want to use 32-bit controls (eg Microsoft Windows Common Controls Mscomctl.ocx) Your VBA code calls a Windows API which uses a 32-bit data type ()

Microsoft Office 365 Versions

The exact version number depends what channel you are on.
More details about the different channels can be found [[here]]

Office Versions

16 = Office 365
16 = Office 2019
16 = Office 2016
15 = Office 2013
14 = Office 2010
12 = Office 2007
11 = Office 2003