Official Answer: Nuvi - SD microSD Card Size - Garmin FAQ

Thanks for the clarification sussamb. I wasn't sure how Express handled that, so it is good to know.

In any case, if you have multiple map files installed on your device, it may be necessary and/or desirable to have a SD card larger than 4 GB.

I may be ordering another micro SD card some for one of my Garmin navigators.

My Garmin Zumo XT will accept a 256 GB card!

https://support.garmin.com/en-US/?faq=UsL6MuMMCM8PpgAhUUCqp7

...but read everything as some special actions may be needed. See below

"microSD/SD memory cards 64 GB or larger cannot be formatted to FAT32 using standard Windows formatting tools. Third-party Windows software may be available which allows the memory card to be formatted in FAT32."

Free disk partitioning software from Paragon or Easeus is arguably the best option for formatting large MicroSD cards in FAT32.

I was thinking about micro SD cards, again, and remembered this post.

It sounds like the simplest thing is to just get 32GB microSD memory cards. That way I can avoid the formatting issue.

Formatting an “oversize” card to FAT32 is certainly not a difficult task. But having said that a 32GB Sandisk card is currently about $12 at Best Buy and around $9 on Amazon. For just the normal use in a GPS, 32GB should be ample for several more years.

An SDHC card and a µSDHC card are different in physical size.
So we are talking about µSDHC cards here.
Any SDHC card is 32GB max.
Fat32 file size is 4GB max.
You can't format anything larger than 32GB to fat32 UNLESS you create multiple partitions.

thank you

I retired a few weeks ago and have been doing some electronics projects around the house. It turns out I had a 32 GB memory card right on my desk until the clutter. So, I deleted some old maps and installed some new ones.

And, yes, I agree that 32GB should be ample for several more years.

Youtube video produced by the former Microsoft engineer who wrote the Windows format routine explaining the Windows format software 32GB size limit:
"Blame Me: The Windows 11 Disk Formatter"
https://www.youtube.com/watch?v=bikbJPI-7Kg&t=45s

The program that I use to format FAT32 single partition μSD cards with sizes greater then 32GB is guiformat.exe. I have formatted many μSD cards with single partitions larger than 32GB without any issues.
"Windows GUI version of fat32format"
http://ridgecrop.co.uk/index.htm?guiformat.htm

A command line version is also available.
"Ridgecrop FAT 32 Formatter"
http://ridgecrop.co.uk/index.htm?fat32format.htm

Mark

My preference is the tool offered by the SD Card Association (Panasonic, Sandisk, Toshiba), SD Memory Card Formatter. It doesn't have a command line version, but does ensure the SD Card is formatted to the specifications given by the companies that set the standard.

https://www.sdcard.org/downloads/formatter/