Help SD Card displays less space used than it actually has

[Papote13]

I have a Samsung Galaxy S4 Active SGH-I537. I let it format my Samsung Class 10 SDHC 64 GB card. It used exFAT format. I then transfered my MP3 collection to it, which is about 34 GB. When I finished, I noticed that I had only 15.4 GB left, so it used up 47 GB! If I check the folders' properties it only displays 7 GB. It doesn't add up.

I am guessing the size allocation might be set to big. Can I format it with a different size allocation on my Windows 7 PC and have it still be compatible with my android phone and regain some more space?

 

[Rukbat]

Install SD Insight. Press the"eye" in the upper-right. That will show you what size the memory chip in there really is. Remember, there's a CPU in the SD card, so it can map a partially defective 64GB card to 50GB of usable space and still have it declaring that it's a 64GB card. I even have a 2GB card that claims (if you put it into a computer) that it's a 16GB card. (That one I don't give back for any amount.)

The first thing I do when buying cards is put them through a few tests to make sure they are what the package says they are and if they aren't (and I've found a few) I have them exchanged.